Merge the 3.41.2 patch into the reuse-schema-3.41 subbranch of reuse-schema

FossilOrigin-Name: 995fa4d09dd15478222eb790da7b5b1a9ffcf5d537f3faa396cd0f9b939fd739

Makefile.in

@@ -140,6 +140,7 @@ GCOV_LDFLAGS1 = -lgcov
 USE_GCOV = @USE_GCOV@
 LTCOMPILE_EXTRAS += $(GCOV_CFLAGS$(USE_GCOV))
 LTLINK_EXTRAS += $(GCOV_LDFLAGS$(USE_GCOV))
+LTCOMPILE_EXTRAS += -DSQLITE_ENABLE_SHARED_SCHEMA
 
 
 # The directory into which to store package information for
@@ -401,6 +402,7 @@ TESTSRC = \
   $(TOP)/src/test_quota.c \
   $(TOP)/src/test_rtree.c \
   $(TOP)/src/test_schema.c \
+  $(TOP)/src/test_schemapool.c \
   $(TOP)/src/test_superlock.c \
   $(TOP)/src/test_syscall.c \
   $(TOP)/src/test_tclsh.c \
@@ -465,6 +467,7 @@ TESTSRC2 = \
   $(TOP)/src/bitvec.c \
   $(TOP)/src/btree.c \
   $(TOP)/src/build.c \
+  $(TOP)/src/callback.c \
   $(TOP)/src/ctime.c \
   $(TOP)/src/date.c \
   $(TOP)/src/dbpage.c \

Makefile.msc

@@ -1513,6 +1513,7 @@ TESTSRC = \
   $(TOP)\src\test_quota.c \
   $(TOP)\src\test_rtree.c \
   $(TOP)\src\test_schema.c \
+  $(TOP)\src\test_schemapool.c \
   $(TOP)\src\test_superlock.c \
   $(TOP)\src\test_syscall.c \
   $(TOP)\src\test_tclsh.c \

VERSION

@@ -1 +1 @@
-3.41.0
+3.41.2

autoconf/tea/configure.ac

@@ -19,7 +19,7 @@ dnl	to configure the system for the local environment.
 # so that we create the export library with the dll.
 #-----------------------------------------------------------------------
 
-AC_INIT([sqlite],[3.41.0])
+AC_INIT([sqlite],[3.41.2])
 
 #--------------------------------------------------------------------
 # Call TEA_INIT as the first TEA_ macro to set up initial vars.

configure

@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.69 for sqlite 3.41.0.
+# Generated by GNU Autoconf 2.69 for sqlite 3.41.2.
 #
 #
 # Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
@@ -726,8 +726,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='sqlite'
 PACKAGE_TARNAME='sqlite'
-PACKAGE_VERSION='3.41.0'
-PACKAGE_STRING='sqlite 3.41.0'
+PACKAGE_VERSION='3.41.2'
+PACKAGE_STRING='sqlite 3.41.2'
 PACKAGE_BUGREPORT=''
 PACKAGE_URL=''
 
@@ -1470,7 +1470,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures sqlite 3.41.0 to adapt to many kinds of systems.
+\`configure' configures sqlite 3.41.2 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1535,7 +1535,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of sqlite 3.41.0:";;
+     short | recursive ) echo "Configuration of sqlite 3.41.2:";;
    esac
   cat <<\_ACEOF
 
@@ -1665,7 +1665,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-sqlite configure 3.41.0
+sqlite configure 3.41.2
 generated by GNU Autoconf 2.69
 
 Copyright (C) 2012 Free Software Foundation, Inc.
@@ -2084,7 +2084,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by sqlite $as_me 3.41.0, which was
+It was created by sqlite $as_me 3.41.2, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   $ $0 $@
@@ -12457,7 +12457,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by sqlite $as_me 3.41.0, which was
+This file was extended by sqlite $as_me 3.41.2, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -12523,7 +12523,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-sqlite config.status 3.41.0
+sqlite config.status 3.41.2
 configured by $0, generated by GNU Autoconf 2.69,
   with options \\"\$ac_cs_config\\"
 

doc/shared_schema.md

@@ -0,0 +1,142 @@
+
+Shared-Schema Mode Notes
+========================
+
+The [reuse-schema](/timeline?r=reuse-schema) branch contains changes 
+to allow SQLite connections to share schemas
+between database connections within the same process in order to save memory.
+Schemas may be shared between multiple databases attached to the same or
+distinct connection handles.
+
+Compile with -DSQLITE\_ENABLE\_SHARED\_SCHEMA in order to enable the
+shared-schema enhancement.  Enabling the shared-schema enhancement causes
+approximately a 0.1% increase in CPU cycles consumed and about a 3000-byte
+increase in the size of the library, even if shared-schema is never used.
+
+Assuming the compile-time requirements are satisfied, the shared-schema
+feature is engaged by opening the database connection using the
+sqlite3_open_v2() API with the SQLITE_OPEN_SHARED_SCHEMA
+flag specified.  The main database and any attached databases will then share
+an in-memory Schema object with any other database opened within the process
+for which: 
+
+  * the contents of the sqlite_master table, including all object names,
+    SQL statements and root pages are identical, and
+  * have the same values for the schema-cookie.
+
+Temp databases (those populated with "CREATE TEMP TABLE" and similar
+statements) never share schemas.
+
+Connections opened with the SQLITE_OPEN_SHARED_SCHEMA flag
+specified may not modify any database schema except that belonging to the
+temp database in anyway. This includes creating or dropping database 
+objects, vacuuming the database, or running ANALYZE when the
+sqlite_stat\[14\] tables do not exist.
+
+For SQLITE_OPEN_SHARED_SCHEMA connections, the
+SQLITE_DBSTATUS_SCHEMA_USED sqlite3_db_status() verb
+distributes the memory used for a shared schema object evenly between all
+database connections that share it.
+
+## The ".shared-schema" Command
+
+The shell tool on this branch contains a special dot-command to help with
+managing databases. The ".shared-schema" dot-command can be used to test
+whether or not two databases are similar enough to share in-memory schemas,
+and to fix minor problems that prevent them from doing so. To test if
+two or more database are compatible, one database is opened directly using 
+the shell tool and the following command issued:
+
+        .shared-schema check <database-1> [<database-2>]...
+
+where &lt;database-1&gt; etc. are replaced with the names of database files
+on disk. For each database specified on the command line, a single line of
+output is produced. If the database can share an in-memory schema with the
+main database opened by the shell tool, the output is of the form:
+
+        <database> is compatible
+
+Otherwise, if the database cannot share a schema with the main db, the output
+is of the form:
+
+        <database> is NOT compatible (<reason>)
+
+where &lt;reason&gt; indicates the cause of the incompatibility. &lt;reason&gt;
+is always one of the following.
+
+<ul>
+  <li> <b>objects</b> - the databases contain a different set schema objects
+  (tables, indexes, views and triggers).
+
+  <li> <b>SQL</b> - the databases contain the same set of objects, but the SQL
+  statements used to create them were not the same.
+
+  <li> <b>root pages</b> - the databases contain the same set of objects created
+  by the same SQL statements, but the root pages are not the same.
+
+  <li> <b>order of sqlite&#95;master rows</b> - the databases contain the same
+  set of objects created by the same SQL statements with the same root pages,
+  but the order of the rows in the sqlite&#95;master tables are different.
+
+  <li> <b>schema cookie</b> - the database schemas are compatible, but the 
+  schema cookie values ("PRAGMA schema&#95;version") are different.
+</ul>
+
+The final three problems in the list above can be fixed using the
+.shared-schema command. To modify such a database so that it can share a 
+schema with the main database, the following shell command is used:
+
+        .shared-schema fix <database-1> [<database-2>]...
+
+If a database can be modified so that it may share a schema with the main
+database opened by the shell tool, output is as follows:
+
+        Fixing <database>... <database> is compatible
+
+If a database does not require modification, or cannot be modified such that
+it can share a schema with the main database, the output of "fix" is identical
+to that of the "check" command.
+
+## Implementation Notes
+
+A single Schema object is never used by more than one database simultaneously,
+regardless of whether or not those databases are attached to the same or
+different database handles. Instead, a pool of schema objects is maintained 
+for each unique sqlite&#95;master-contents/schema-cookie combination
+opened within the process. Each time database schemas are required by a
+connection, for example as part of an sqlite3&#95;prepare\*(),
+sqlite3&#95;blob&#95;open() or sqlite3&#95;blob&#95;open() call, it obtains
+the minimum number of schemas required from the various schema-pools, returning
+them at the end of the call. This means that a single schema-pool only ever
+contains more than one copy of the schema if:
+
+  * Two threads require schemas from the same pool at the same time, or
+  * A single sqlite3&#95;prepare\*() call requires schemas for two or more
+    attached databases that use the same schema-pool.
+
+The size of a schema-pool never shrinks. Each schema pool always maintains 
+a number of schema objects equal to the highwater mark of schema objects
+simultaneously required by clients.
+
+This approach is preferred to allowing multiple databases to use the same
+Schema object simultaneously for three reasons:
+
+  * The Schema object is not completely read-only. For example, the 
+    Index.zIdxAff string is allocated lazily.
+  * Throughout the statement compiler, SQLite uses variables like 
+    Table.pSchema and Index.pSchema with the sqlite3SchemaToIndex() routine
+    in order to determine which attached database a Table or Index object
+    resides in. This mechanism does not work if the same Schema may be
+    used by two or more attached databases.
+  * It may be easier to modify this approach in order to allow
+    SQLITE&#95;OPEN&#95;SHARED&#95;SCHEMA connections to modify database
+    schemas, should that be required.
+
+SQLITE&#95;OPEN&#95;SHARED&#95;SCHEMA connections do not store their
+virtual-table handles in the Table.pVTable list of each table. This would not
+work, as (a) there is no guarantee that a connection will be assigned the same
+Schema object each time it requests one from a schema-pool and (b) a single
+Schema (and therefore Table) object may correspond to tables in two or more
+databases attached to a single connection. Instead, all virtual-table handles
+associated with a single database are stored in a linked-list headed at
+Db.pVTable.

ext/fts3/fts3_write.c

@@ -2667,16 +2667,18 @@ static int fts3MsrBufferData(
   char *pList,
   i64 nList
 ){
-  if( nList>pMsr->nBuffer ){
+  if( (nList+FTS3_NODE_PADDING)>pMsr->nBuffer ){
     char *pNew;
-    pMsr->nBuffer = nList*2;
-    pNew = (char *)sqlite3_realloc64(pMsr->aBuffer, pMsr->nBuffer);
+    int nNew = nList*2 + FTS3_NODE_PADDING;
+    pNew = (char *)sqlite3_realloc64(pMsr->aBuffer, nNew);
     if( !pNew ) return SQLITE_NOMEM;
     pMsr->aBuffer = pNew;
+    pMsr->nBuffer = nNew;
   }
 
   assert( nList>0 );
   memcpy(pMsr->aBuffer, pList, nList);
+  memset(&pMsr->aBuffer[nList], 0, FTS3_NODE_PADDING);
   return SQLITE_OK;
 }
 

ext/recover/dbdata.c

@@ -512,10 +512,14 @@ static int dbdataNext(sqlite3_vtab_cursor *pCursor){
         if( pCsr->bOnePage==0 && pCsr->iPgno>pCsr->szDb ) return SQLITE_OK;
         rc = dbdataLoadPage(pCsr, pCsr->iPgno, &pCsr->aPage, &pCsr->nPage);
         if( rc!=SQLITE_OK ) return rc;
-        if( pCsr->aPage ) break;
+        if( pCsr->aPage && pCsr->nPage>=256 ) break;
+        sqlite3_free(pCsr->aPage);
+        pCsr->aPage = 0;
         if( pCsr->bOnePage ) return SQLITE_OK;
         pCsr->iPgno++;
       }
+
+      assert( iOff+3+2<=pCsr->nPage );
       pCsr->iCell = pTab->bPtr ? -2 : 0;
       pCsr->nCell = get_uint16(&pCsr->aPage[iOff+3]);
     }
@@ -750,8 +754,7 @@ static int dbdataGetEncoding(DbdataCursor *pCsr){
   int nPg1 = 0;
   u8 *aPg1 = 0;
   rc = dbdataLoadPage(pCsr, 1, &aPg1, &nPg1);
-  assert( rc!=SQLITE_OK || nPg1==0 || nPg1>=512 );
-  if( rc==SQLITE_OK && nPg1>0 ){
+  if( rc==SQLITE_OK && nPg1>=(56+4) ){
     pCsr->enc = get_uint32(&aPg1[56]);
   }
   sqlite3_free(aPg1);

ext/wasm/EXPORTED_FUNCTIONS.fiddle

@@ -1,10 +1,7 @@
+_fiddle_exec
+_fiddle_interrupt
+_fiddle_experiment
+_fiddle_the_db
 _fiddle_db_arg
 _fiddle_db_filename
-_fiddle_exec
-_fiddle_experiment
-_fiddle_interrupt
-_fiddle_main
 _fiddle_reset_db
-_fiddle_db_handle
-_fiddle_db_vfs
-_fiddle_export_db

ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-api

@@ -1,8 +1,3 @@
-_malloc
-_free
-_realloc
-_sqlite3_aggregate_context
-_sqlite3_auto_extension
 _sqlite3_bind_blob
 _sqlite3_bind_double
 _sqlite3_bind_int
@@ -10,16 +5,11 @@ _sqlite3_bind_int64
 _sqlite3_bind_null
 _sqlite3_bind_parameter_count
 _sqlite3_bind_parameter_index
-_sqlite3_bind_pointer
 _sqlite3_bind_text
-_sqlite3_busy_handler
-_sqlite3_busy_timeout
-_sqlite3_cancel_auto_extension
 _sqlite3_changes
 _sqlite3_changes64
 _sqlite3_clear_bindings
 _sqlite3_close_v2
-_sqlite3_collation_needed
 _sqlite3_column_blob
 _sqlite3_column_bytes
 _sqlite3_column_count
@@ -30,28 +20,12 @@ _sqlite3_column_int64
 _sqlite3_column_name
 _sqlite3_column_text
 _sqlite3_column_type
-_sqlite3_column_value
-_sqlite3_commit_hook
 _sqlite3_compileoption_get
 _sqlite3_compileoption_used
-_sqlite3_complete
-_sqlite3_context_db_handle
-_sqlite3_create_collation
-_sqlite3_create_collation_v2
-_sqlite3_create_function
 _sqlite3_create_function_v2
-_sqlite3_create_module
-_sqlite3_create_module_v2
-_sqlite3_create_window_function
 _sqlite3_data_count
 _sqlite3_db_filename
-_sqlite3_db_handle
 _sqlite3_db_name
-_sqlite3_db_status
-_sqlite3_declare_vtab
-_sqlite3_deserialize
-_sqlite3_drop_modules
-_sqlite3_errcode
 _sqlite3_errmsg
 _sqlite3_error_offset
 _sqlite3_errstr
@@ -59,38 +33,16 @@ _sqlite3_exec
 _sqlite3_expanded_sql
 _sqlite3_extended_errcode
 _sqlite3_extended_result_codes
-_sqlite3_file_control
 _sqlite3_finalize
-_sqlite3_free
-_sqlite3_get_auxdata
 _sqlite3_initialize
-_sqlite3_keyword_count
-_sqlite3_keyword_name
-_sqlite3_keyword_check
-_sqlite3_last_insert_rowid
+_sqlite3_interrupt
 _sqlite3_libversion
 _sqlite3_libversion_number
-_sqlite3_limit
-_sqlite3_malloc
-_sqlite3_malloc64
-_sqlite3_msize
 _sqlite3_open
 _sqlite3_open_v2
-_sqlite3_overload_function
 _sqlite3_prepare_v2
 _sqlite3_prepare_v3
-_sqlite3_preupdate_blobwrite
-_sqlite3_preupdate_count
-_sqlite3_preupdate_depth
-_sqlite3_preupdate_hook
-_sqlite3_preupdate_new
-_sqlite3_preupdate_old
-_sqlite3_progress_handler
-_sqlite3_randomness
-_sqlite3_realloc
-_sqlite3_realloc64
 _sqlite3_reset
-_sqlite3_reset_auto_extension
 _sqlite3_result_blob
 _sqlite3_result_double
 _sqlite3_result_error
@@ -98,106 +50,23 @@ _sqlite3_result_error_code
 _sqlite3_result_error_nomem
 _sqlite3_result_error_toobig
 _sqlite3_result_int
-_sqlite3_result_int64
 _sqlite3_result_null
-_sqlite3_result_pointer
-_sqlite3_result_subtype
 _sqlite3_result_text
-_sqlite3_result_zeroblob
-_sqlite3_result_zeroblob64
-_sqlite3_rollback_hook
-_sqlite3_serialize
-_sqlite3_set_authorizer
-_sqlite3_set_auxdata
-_sqlite3_set_last_insert_rowid
-_sqlite3_shutdown
 _sqlite3_sourceid
 _sqlite3_sql
-_sqlite3_status
-_sqlite3_status64
 _sqlite3_step
-_sqlite3_stmt_isexplain
-_sqlite3_stmt_readonly
-_sqlite3_stmt_status
 _sqlite3_strglob
-_sqlite3_stricmp
 _sqlite3_strlike
-_sqlite3_strnicmp
-_sqlite3_table_column_metadata
 _sqlite3_total_changes
 _sqlite3_total_changes64
-_sqlite3_trace_v2
-_sqlite3_txn_state
-_sqlite3_update_hook
-_sqlite3_uri_boolean
-_sqlite3_uri_int64
-_sqlite3_uri_key
-_sqlite3_uri_parameter
-_sqlite3_user_data
 _sqlite3_value_blob
 _sqlite3_value_bytes
 _sqlite3_value_double
-_sqlite3_value_dup
-_sqlite3_value_free
-_sqlite3_value_frombind
-_sqlite3_value_int
-_sqlite3_value_int64
-_sqlite3_value_nochange
-_sqlite3_value_numeric_type
-_sqlite3_value_pointer
-_sqlite3_value_subtype
 _sqlite3_value_text
 _sqlite3_value_type
 _sqlite3_vfs_find
 _sqlite3_vfs_register
-_sqlite3_vfs_unregister
-_sqlite3_vtab_collation
-_sqlite3_vtab_distinct
-_sqlite3_vtab_in
-_sqlite3_vtab_in_first
-_sqlite3_vtab_in_next
-_sqlite3_vtab_nochange
-_sqlite3_vtab_on_conflict
-_sqlite3_vtab_rhs_value
-_sqlite3changegroup_add
-_sqlite3changegroup_add_strm
-_sqlite3changegroup_delete
-_sqlite3changegroup_new
-_sqlite3changegroup_output
-_sqlite3changegroup_output_strm
-_sqlite3changeset_apply
-_sqlite3changeset_apply_strm
-_sqlite3changeset_apply_v2
-_sqlite3changeset_apply_v2_strm
-_sqlite3changeset_concat
-_sqlite3changeset_concat_strm
-_sqlite3changeset_conflict
-_sqlite3changeset_finalize
-_sqlite3changeset_fk_conflicts
-_sqlite3changeset_invert
-_sqlite3changeset_invert_strm
-_sqlite3changeset_new
-_sqlite3changeset_next
-_sqlite3changeset_old
-_sqlite3changeset_op
-_sqlite3changeset_pk
-_sqlite3changeset_start
-_sqlite3changeset_start_strm
-_sqlite3changeset_start_v2
-_sqlite3changeset_start_v2_strm
-_sqlite3session_attach
-_sqlite3session_changeset
-_sqlite3session_changeset_size
-_sqlite3session_changeset_strm
-_sqlite3session_config
-_sqlite3session_create
-_sqlite3session_delete
-_sqlite3session_diff
-_sqlite3session_enable
-_sqlite3session_indirect
-_sqlite3session_isempty
-_sqlite3session_memory_used
-_sqlite3session_object_config
-_sqlite3session_patchset
-_sqlite3session_patchset_strm
-_sqlite3session_table_filter
+_sqlite3_wasm_db_error
+_sqlite3_wasm_enum_json
+_malloc
+_free

ext/wasm/fiddle/fiddle.html

@@ -273,6 +273,11 @@
         </fieldset>
       </div>
     </div> <!-- #view-split -->
+    <!-- Maintenance notes:
+
+        ... TODO... currently being refactored...
+
+    -->
     <script src="fiddle.js"></script>
   </body>
 </html>

main.mk

@@ -326,6 +326,7 @@ TESTSRC = \
   $(TOP)/src/test_quota.c \
   $(TOP)/src/test_rtree.c \
   $(TOP)/src/test_schema.c \
+  $(TOP)/src/test_schemapool.c \
   $(TOP)/src/test_sqllog.c \
   $(TOP)/src/test_superlock.c \
   $(TOP)/src/test_syscall.c \
@@ -384,6 +385,7 @@ TESTSRC2 = \
   $(TOP)/src/backup.c \
   $(TOP)/src/btree.c \
   $(TOP)/src/build.c \
+  $(TOP)/src/callback.c \
   $(TOP)/src/date.c \
   $(TOP)/src/dbpage.c \
   $(TOP)/src/dbstat.c \

manifest

@@ -1,13 +1,13 @@
-C Version\s3.41.0
-D 2023-02-21T18:09:37.622
+C Merge\sthe\s3.41.2\spatch\sinto\sthe\sreuse-schema-3.41\ssubbranch\sof\sreuse-schema
+D 2023-03-22T13:47:05.547
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
-F Makefile.in 594f07f8829020a45d825234edf14046544b5bf6bc0057a9d5b83b58686b1c46
+F Makefile.in 7b1474d9ccdae980544a2c73abdcba0c72659045563f441afd97f8f39a6e1a76
 F Makefile.linux-gcc f609543700659711fbd230eced1f01353117621dccae7b9fb70daa64236c5241
-F Makefile.msc b0026b61d1242add00c28dbe169271a763fffcb3af6762bcdbeb20c3efe6a69f
+F Makefile.msc 670510db11ce69d9a22d299636f64a4fa309f0e95c91dd4fef3c694b64c87362
 F README.md 8b8df9ca852aeac4864eb1e400002633ee6db84065bd01b78c33817f97d31f5e
-F VERSION 413ec94920a487ae32c9a2a8819544d690662d6f7c7ce025c0d0b8a1e74fa9db
+F VERSION b0157838cb8e50bf2bc42bb69fc1426e6e6a4b705f6a9cdfe7d5b4d40b85f43b
 F aclocal.m4 a5c22d164aff7ed549d53a90fa56d56955281f50
 F art/sqlite370.eps aa97a671332b432a54e1d74ff5e8775be34200c2
 F art/sqlite370.ico af56c1d00fee7cd4753e8631ed60703ed0fc6e90
@@ -22,7 +22,7 @@ F autoconf/configure.ac ec7fa914c5e74ff212fe879f9bb6918e1234497e05facfb641f30c4d
 F autoconf/tea/Makefile.in 106a96f2f745d41a0f6193f1de98d7355830b65d45032c18cd7c90295ec24196
 F autoconf/tea/README 3e9a3c060f29a44344ab50aec506f4db903fb873
 F autoconf/tea/aclocal.m4 52c47aac44ce0ddb1f918b6993e8beb8eee88f43
-F autoconf/tea/configure.ac d1eaa72f4d202ca106f4b2762733709d3f89a877da2e385a57881c4ad0427be7
+F autoconf/tea/configure.ac 9891bfd342d17505b6f69858ab3be1ba4416bfe64b8abcb577f32ebadade7a3b
 F autoconf/tea/doc/sqlite3.n e1fe45d4f5286ee3d0ccc877aca2a0def488e9bb
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 F autoconf/tea/pkgIndex.tcl.in b9eb6dd37f64e08e637d576b3c83259814b9cddd78bec4af2e5abfc6c5c750ce
@@ -33,13 +33,14 @@ F autoconf/tea/win/nmakehlp.c b01f822eabbe1ed2b64e70882d97d48402b42d2689a1ea0034
 F autoconf/tea/win/rules.vc c511f222b80064096b705dbeb97060ee1d6b6d63
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 F config.sub c2d0260f17f3e4bc0b6808fccf1b291cb5e9126c14fc5890efc77b9fd0175559
-F configure 6ba84abf7878bb072d460766d29e492028468775d4c09464940343092eb6493c x
+F configure e3cc91e4da6fff443dcd010ba3acd12053ab111e5021c84ebdfb84ed1aa67898 x
 F configure.ac 4654d32ac0a0d0b48f1e1e79bdc3d777b723cf2f63c33eb1d7c4ed8b435938e8
 F contrib/sqlitecon.tcl 210a913ad63f9f991070821e599d600bd913e0ad
 F doc/F2FS.txt c1d4a0ae9711cfe0e1d8b019d154f1c29e0d3abfe820787ba1e9ed7691160fcd
 F doc/json-enhancements.md e356fc834781f1f1aa22ee300027a270b2c960122468499bf347bb123ce1ea4f
 F doc/lemon.html efc0cd2345d66905505d98f862e1c571512def0ceb5b016cb658fd4918eb76a3
 F doc/pager-invariants.txt 27fed9a70ddad2088750c4a2b493b63853da2710
+F doc/shared_schema.md 759fc374709fccf4e5d2d0cbd05f8fedd38fb022bdd8a6c5b5f492684c7023b9
 F doc/trusted-schema.md 33625008620e879c7bcfbbfa079587612c434fa094d338b08242288d358c3e8a
 F doc/vdbesort-memory.md 4da2639c14cd24a31e0af694b1a8dd37eaf277aff3867e9a8cc14046bc49df56
 F doc/vfs-shm.txt e101f27ea02a8387ce46a05be2b1a902a021d37a
@@ -76,7 +77,7 @@ F ext/fts3/fts3_tokenizer.h 64c6ef6c5272c51ebe60fc607a896e84288fcbc3
 F ext/fts3/fts3_tokenizer1.c c1de4ae28356ad98ccb8b2e3388a7fdcce7607b5523738c9afb6275dab765154
 F ext/fts3/fts3_unicode.c de426ff05c1c2e7bce161cf6b706638419c3a1d9c2667de9cb9dc0458c18e226
 F ext/fts3/fts3_unicode2.c 416eb7e1e81142703520d284b768ca2751d40e31fa912cae24ba74860532bf0f
-F ext/fts3/fts3_write.c 4fb644df0ff840267e47a724286c7a1fa5540273a7ce15756dd5913a101ec302
+F ext/fts3/fts3_write.c 33d2d0db4dd4e7a7a7e9a7f790414293277f9e7682a2fd9d61c713bfc37cd8b6
 F ext/fts3/fts3speed.tcl b54caf6a18d38174f1a6e84219950d85e98bb1e9
 F ext/fts3/tool/fts3cov.sh c331d006359456cf6f8f953e37f2b9c7d568f3863f00bb5f7eb87fea4ac01b73
 F ext/fts3/tool/fts3view.c 413c346399159df81f86c4928b7c4a455caab73bfbc8cd68f950f632e5751674
@@ -365,7 +366,7 @@ F ext/rbu/rbuvacuum4.test ffccd22f67e2d0b380d2889685742159dfe0d19a3880ca3d2d1d69
 F ext/rbu/sqlite3rbu.c 348bb6251e6ec459de102f8b2dd50789a98643ef7a28e56e4c787ac9659c15ea
 F ext/rbu/sqlite3rbu.h 9d923eb135c5d04aa6afd7c39ca47b0d1d0707c100e02f19fdde6a494e414304
 F ext/rbu/test_rbu.c ee6ede75147bc081fe9bc3931e6b206277418d14d3fbceea6fdc6216d9b47055
-F ext/recover/dbdata.c dc25628e405c86936c597e28f3e6f56a257029c3034c5ef7f6b10f7c02f41018
+F ext/recover/dbdata.c 81115741d685f25cbeb52e233afc5b510bf2a144ea802eb7b64da2b95dc9b274
 F ext/recover/recover1.test 2072993624d5e32fef20ae03b17fc06c02bcb344421fe17bb329b24d2a51e647
 F ext/recover/recover_common.tcl a61306c1eb45c0c3fc45652c35b2d4ec19729e340bdf65a272ce4c229cefd85a
 F ext/recover/recoverclobber.test 3ba6c0c373c5c63d17e82eced64c05c57ccaf26c1abe1ca7141334022a79f32e
@@ -466,11 +467,11 @@ F ext/session/test_session.c 2de472b4d7e62e85ca1992094612725e2450a77dbf7523db64d
 F ext/userauth/sqlite3userauth.h 7f3ea8c4686db8e40b0a0e7a8e0b00fac13aa7a3
 F ext/userauth/user-auth.txt e6641021a9210364665fe625d067617d03f27b04
 F ext/userauth/userauth.c 7f00cded7dcaa5d47f54539b290a43d2e59f4b1eb5f447545fa865f002fc80cb
-F ext/wasm/EXPORTED_FUNCTIONS.fiddle.in 27450c8b8c70875a260aca55435ec927068b34cef801a96205adb81bdcefc65c
+F ext/wasm/EXPORTED_FUNCTIONS.fiddle 7fb73f7150ab79d83bb45a67d257553c905c78cd3d693101699243f36c5ae6c3
 F ext/wasm/GNUmakefile 5418b4702f4ad0f2162a7e0d128042e8d9219827e3d36978bd2dd6e26ce8f68e
 F ext/wasm/README-dist.txt 6382cb9548076fca472fb3330bbdba3a55c1ea0b180ff9253f084f07ff383576
 F ext/wasm/README.md ef39861aa21632fdbca0bdd469f78f0096f6449a720f3f39642594af503030e9
-F ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-api d6a5078f48a5301ed17b9a30331075d9b2506e1360c1f0dee0c7816c10acd9ab
+F ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-api c5eaceabb9e759aaae7d3101a4a3e542f96ab2c99d89a80ce20ec18c23115f33
 F ext/wasm/api/EXPORTED_RUNTIME_METHODS.sqlite3-api 1ec3c73e7d66e95529c3c64ac3de2470b0e9e7fbf7a5b41261c367cf4f1b7287
 F ext/wasm/api/README.md 77a2f1f2fc60a35def7455dffc8d3f2c56385d6ac5c6cecc60fa938252ea2c54
 F ext/wasm/api/extern-post-js.c-pp.js 44a3a169f55a8dba42cf688954b2625b9b9e6174f2ff02d4918a2ca8c3beab7f
@@ -511,8 +512,8 @@ F ext/wasm/dist.make f55f9c9e1980ea11a59964e59535c66175a17f004d1c2e274522c3366b3
 F ext/wasm/fiddle.make 396a0d6e2b3aa63ad448ea71d91676cb9cbbba8f5e6529cf1248d17f29142f47
 F ext/wasm/fiddle/emscripten.css 3d253a6fdb8983a2ac983855bfbdd4b6fa1ff267c28d69513dd6ef1f289ada3f
 F ext/wasm/fiddle/fiddle-worker.js 163d6139a93fab4bcb72064923df050d4e7c0ff0d8aa061ce8776a6e75da8a10
+F ext/wasm/fiddle/fiddle.html 550c5aafce40bd218de9bf26192749f69f9b10bc379423ecd2e162bcef885c08
 F ext/wasm/fiddle/fiddle.js 974b995119ac443685d7d94d3b3c58c6a36540e9eb3fed7069d5653284071715
-F ext/wasm/fiddle/index.html 5daf54e8f3d7777cbb1ca4f93affe28858dbfff25841cb4ab81d694efed28ec2
 F ext/wasm/index-dist.html 22379774f0ad4edcaaa8cf9c674c82e794cc557719a8addabed74eb8069d412e
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 F ext/wasm/jaccwabyt/jaccwabyt.js 06f2ef1ad640c26c593def3d960336e9bb789819b920516480895c38ed5f58fa
@@ -540,7 +541,7 @@ F ext/wasm/wasmfs.make cf9a68162d92ca2bcb0b9528b244cb36d5cc2d84ccc9c2d398461927d
 F install-sh 9d4de14ab9fb0facae2f48780b874848cbf2f895 x
 F ltmain.sh 3ff0879076df340d2e23ae905484d8c15d5fdea8
 F magic.txt 5ade0bc977aa135e79e3faaea894d5671b26107cc91e70783aa7dc83f22f3ba0
-F main.mk ac6b13f8ecc43f377e9912380ea4cf366051d7f784cf61c8886e03e1cf0fbefa
+F main.mk 32aeed442b4625ca0d7959e5d33fbe72b2bcce74a005af5baaf791a4926ab5d9
 F mkso.sh fd21c06b063bb16a5d25deea1752c2da6ac3ed83
 F mptest/config01.test 3c6adcbc50b991866855f1977ff172eb6d901271
 F mptest/config02.test 4415dfe36c48785f751e16e32c20b077c28ae504
@@ -553,28 +554,28 @@ F sqlite.pc.in 42b7bf0d02e08b9e77734a47798d1a55a9e0716b
 F sqlite3.1 fc7ad8990fc8409983309bb80de8c811a7506786
 F sqlite3.pc.in 48fed132e7cb71ab676105d2a4dc77127d8c1f3a
 F sqlite_cfg.h.in baf2e409c63d4e7a765e17769b6ff17c5a82bbd9cbf1e284fd2e4cefaff3fcf2
-F src/alter.c 3ca2f449c890f8b86ec9e06f0c4fccf0648941c3308a16904cb2852227db83f7
-F src/analyze.c b597c382f23b19cce563211181e84b7e8edddd6871d5f630bbadedb57e562806
-F src/attach.c cc9d00d30da916ff656038211410ccf04ed784b7564639b9b61d1839ed69fd39
+F src/alter.c dab37a80032366d27a415d7a769aa1a7bba2358424f1f67dd910e25ffffe055f
+F src/analyze.c 594f0137ba2682cbbde286b2fed4d43b22054b4900d2f900a69a7555f9a4e4d7
+F src/attach.c 2af98700f1a3867a78475aa164571a2fbacce09c681076b01b119ef31b8ef4ac
 F src/auth.c f4fa91b6a90bbc8e0d0f738aa284551739c9543a367071f55574681e0f24f8cf
 F src/backup.c a2891172438e385fdbe97c11c9745676bec54f518d4447090af97189fd8e52d7
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 F src/btmutex.c 6ffb0a22c19e2f9110be0964d0731d2ef1c67b5f7fabfbaeb7b9dabc4b7740ca
-F src/btree.c 2f012aea074de6319c191cbf5c45034de79bf1c762826e381b1cf75421d8d831
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 F src/btree.h aa354b9bad4120af71e214666b35132712b8f2ec11869cb2315c52c81fad45cc
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-F src/callback.c 4cd7225b26a97f7de5fee5ae10464bed5a78f2adefe19534cc2095b3a8ca484a
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 F src/complete.c a3634ab1e687055cd002e11b8f43eb75c17da23e
-F src/ctime.c 20507cc0b0a6c19cd882fcd0eaeda32ae6a4229fb4b024cfdf3183043d9b703d
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 F src/date.c f21815ca7172ce073db3163ac54c8d9f2841077165c1a6123b4d1c376a0c7ec7
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 F src/dbstat.c ec92074baa61d883de58c945162d9e666c13cd7cf3a23bc38b4d1c4d0b2c2bef
-F src/delete.c 86573edae75e3d3e9a8b590d87db8e47222103029df4f3e11fa56044459b514e
-F src/expr.c 2e5e67e800c9416996df52409746a2f3c7dadf5d38b5a367ce379b239e3f40c8
+F src/delete.c 201fe0763c52783d205c8c13cdd9d55c1bd5cb21c1f036753f99103b43284b90
+F src/expr.c e7c0cdde3bc5e5b82b02264547456e4454e1ea5a91b9649b3a02b6422a660122
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c 722f20779f5342a787922deded3628d8c74b5249cab04098cf17ee2f2aaff002
-F src/func.c 64c4cb2eebf6ddb6b4b08dc17790e7152b887f223f8caf0c0fe96da1c5a876ca
+F src/func.c d187be57a886ddf4e6b7ef584a494361899be3df5eee6d4a747b68ff4aff4122
 F src/global.c e06ff8e0acd85aec13563c9ecb44fbbf38232ccf73594998fd880b92d619594b
 F src/hash.c c6af5f96a7a76d000f07c5402c48c318c2566beecdee9e78b9d9f60ce7119565
 F src/hash.h 3340ab6e1d13e725571d7cee6d3e3135f0779a7d8e76a9ce0a85971fa3953c51
@@ -584,7 +585,7 @@ F src/insert.c 1b11a2e33ee52db93c02fddac67e39d00161d61b69fac2675b82f2aa68c1b61c
 F src/json.c c85ed6fce06f43d414b0d7fff64749d43a0dbd1067123ee407bd3a0752454161
 F src/legacy.c d7874bc885906868cd51e6c2156698f2754f02d9eee1bae2d687323c3ca8e5aa
 F src/loadext.c b04eb648cedc45efe4298e1ef439ac4f0096ae27b5f01accb0a1f49d57789128
-F src/main.c f5ed7b748d7e54b96ac577a9d87af9461f13f092bbe684d473448010333402dc
+F src/main.c bcccf06ba1c14853bfaa71ea7758b9c5b1b845b5b59e43ea717e05fb8fbdf8d4
 F src/malloc.c 47b82c5daad557d9b963e3873e99c22570fb470719082c6658bf64e3012f7d23
 F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c c12a42539b1ba105e3707d0e628ad70e611040d8f5e38cf942cee30c867083de
@@ -611,26 +612,26 @@ F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
 F src/pager.c 39af8ff7c73a991f61f4d1e3a6f8f98b1c8e29144723507822774cac5e6ee0b5
 F src/pager.h f82e9844166e1585f5786837ddc7709966138ced17f568c16af7ccf946c2baa3
 F src/parse.y 960d2da92a23f8ba2ca22748a51bd75ee2c575564f2cbc59f119640e7f5b4c5d
-F src/pcache.c f4268f7f73c6a3db12ce22fd25bc68dc42315d19599414ab1207d7cf32f79197
-F src/pcache.h 4f87acd914cef5016fae3030343540d75f5b85a1877eed1a2a19b9f284248586
+F src/pcache.c 842410539b544e12d5fccfcf29890782f46a58f227a77bc0bd76243799662c0c
+F src/pcache.h 1497ce1b823cf00094bb0cf3bac37b345937e6f910890c626b16512316d3abf5
 F src/pcache1.c dee95e3cd2b61e6512dc814c5ab76d5eb36f0bfc9441dbb4260fccc0d12bbddc
-F src/pragma.c 82d5090a35eac75876d3b41f48d06b2370553c9576bf2942233c462e03eb94c9
-F src/pragma.h e690a356c18e98414d2e870ea791c1be1545a714ba623719deb63f7f226d8bb7
-F src/prepare.c ce87a08cfddd45a147150db34190b1986f2d4a0e0828858cb6bd908c78fb02e3
+F src/pragma.c 5db436bd36a6b8f007c6ec0bb62aab4fe7e4ceb9c3bd4a49e74847d87bce30b6
+F src/pragma.h 50f6d3b408ed56bde4f4e4aead8c0b2022030b692e8de237c1b7a0b5ce87a0c8
+F src/prepare.c 42a8566557fb7a6283bfe305d13aa6993dd3d956bcf00ad0d6924045c5abec03
 F src/printf.c ff4b05e38bf928ff1b80d3dda4f977b10fe39ecbfe69c018224c7e5594fb2455
 F src/random.c 606b00941a1d7dd09c381d3279a058d771f406c5213c9932bbd93d5587be4b9c
-F src/resolve.c d62c5665279cc7485f9d45b5e20911cc7b19c203f268321a90d05d74f4725750
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 F src/rowset.c ba9515a922af32abe1f7d39406b9d35730ed65efab9443dc5702693b60854c92
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-F src/shell.c.in 6f36f5ca05f1bebf74935a7fcf2dce983016e807a09cbd752a673583ad7da087
-F src/sqlite.h.in 662a2fa083d093896b92560c871dea6d86792b49dc4bf7b4e8dbeca8e7171488
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+F src/shell.c.in 9823f24adaee6f5cfe8e0a3745172e80963e55a2a09d64fdf59e06ab33031fca
+F src/sqlite.h.in 513303c006a00cc0a50d4dfe47bd58928e47a402145fba417708e9769886077c
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h da473ce2b3d0ae407a6300c4a164589b9a6bfdbec9462688a8593ff16f3bb6e4
-F src/sqliteInt.h 4dcc36b21dd0c77efeb0bb38b0d31916bc63fb429c8a89d186c945eba0816447
+F src/sqliteInt.h eda83f827e01373db7607030db411f359c09b93aee60158102f78d88c073c465
 F src/sqliteLimit.h d7323ffea5208c6af2734574bae933ca8ed2ab728083caa117c9738581a31657
-F src/status.c 160c445d7d28c984a0eae38c144f6419311ed3eace59b44ac6dafc20db4af749
+F src/status.c 501433a8bdf64be125746a53bb9180761f9364428b59b318365eb88afd6d5cea
 F src/table.c 0f141b58a16de7e2fbe81c308379e7279f4c6b50eb08efeec5892794a0ba30d1
-F src/tclsqlite.c 8522a04fb9c84faa1d80354430ae0ee9349727a3a4b32e3cfe39b9be8324cabd
+F src/tclsqlite.c be4795cda32a6dd448578320b04b95ecce09ad0d7aeb95ede203c91af31b81fd
 F src/test1.c 29ab8aca939818a61bf791e4ff5d45df6da30940c0980dcf502562b925de4e05
 F src/test2.c 827446e259a3b7ab949da1542953edda7b5117982576d3e6f1c24a0dd20a5cef
 F src/test3.c 61798bb0d38b915067a8c8e03f5a534b431181f802659a6616f9b4ff7d872644
@@ -645,7 +646,7 @@ F src/test_backup.c bf5da90c9926df0a4b941f2d92825a01bbe090a0
 F src/test_bestindex.c 68c62586d2ae9f032903fe53be743657d0c2aac0a850b880938b668e1161d516
 F src/test_blob.c ae4a0620b478548afb67963095a7417cd06a4ec0a56adb453542203bfdcb31ce
 F src/test_btree.c 8b2dc8b8848cf3a4db93f11578f075e82252a274
-F src/test_config.c 8264637b06a3c1f0727c88d1ea32dcf7986b9e7e358a970cae87cdac8a5b2708
+F src/test_config.c 73ebdc35580900d12c20b984db9ec1abe860dc75f66ae703f2b6fc9d95e09dc1
 F src/test_delete.c e2fe07646dff6300b48d49b2fee2fe192ed389e834dd635e3b3bac0ce0bf9f8f
 F src/test_demovfs.c 38a459d1c78fd9afa770445b224c485e079018d6ac07332ff9bd07b54d2b8ce9
 F src/test_devsym.c aff2255ea290d7718da08af30cdf18e470ff7325a5eff63e0057b1496ed66593
@@ -669,10 +670,11 @@ F src/test_quota.c 6cb9297115b551f433a9ad1741817a9831abed99
 F src/test_quota.h 2a8ad1952d1d2ca9af0ce0465e56e6c023b5e15d
 F src/test_rtree.c 671f3fae50ff116ef2e32a3bf1fe21b5615b4b7b
 F src/test_schema.c f5d6067dfc2f2845c4dd56df63e66ee826fb23877855c785f75cc2ca83fd0c1b
+F src/test_schemapool.c ae21a79f9bc7e9099ae78dbd46d5c28ee75330e62e3256a9fde25564ff9df492
 F src/test_sqllog.c 540feaea7280cd5f926168aee9deb1065ae136d0bbbe7361e2ef3541783e187a
 F src/test_superlock.c 4839644b9201da822f181c5bc406c0b2385f672e
 F src/test_syscall.c 1073306ba2e9bfc886771871a13d3de281ed3939
-F src/test_tclsh.c 3ff5d188a72f00807425954ea3b493dfd3a4b890ecc6700ea83bad2fd1332ecf
+F src/test_tclsh.c 15c29f9eb00907b361c2c3b11d0897256c8eeef3bdc5f1f169db044ab96b18e7
 F src/test_tclvar.c 33ff42149494a39c5fbb0df3d25d6fafb2f668888e41c0688d07273dcb268dfc
 F src/test_thread.c 7ddcf0c8b79fa3c1d172f82f322302c963d923cdb503c6171f3c8081586d0b01
 F src/test_vdbecov.c f60c6f135ec42c0de013a1d5136777aa328a776d33277f92abac648930453d43
@@ -685,31 +687,31 @@ F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
 F src/threads.c 4ae07fa022a3dc7c5beb373cf744a85d3c5c6c3c
 F src/tokenize.c 1305797eab3542a0896b552c6e7669c972c1468e11e92b370533c1f37a37082b
 F src/treeview.c fccf3b8c517c1f55cb380c1522febe6921fcb2bd800c16c78cab571d0eb0ccbd
-F src/trigger.c 5e68b790f022b8dafbfb0eb244786512a95c9575fc198719d2557d73e5795858
-F src/update.c f118e51768d2c1309e3c81e9f91141b22b8a1339cbc5969b1b2d810feaa25b22
+F src/trigger.c d2f0bf0ed0f00799f5176332827be67ecd154f0e94321455183febef6007b2b4
+F src/update.c 76664e1beae86e8e961983ebe19a4ee9ebd7e26683ead2b288ba08f81fc7ba4e
 F src/upsert.c 5303dc6c518fa7d4b280ec65170f465c7a70b7ac2b22491598f6d0b4875b3145
 F src/utf.c ee39565f0843775cc2c81135751ddd93eceb91a673ea2c57f61c76f288b041a0
 F src/util.c 3ff7bc2b48dd425b1448304bb86273b05da1621f136d51dbb9789f8803559a1f
-F src/vacuum.c 84ce7f01f8a7a08748e107a441db83bcec13970190ddcb0c9ff522adbc1c23fd
-F src/vdbe.c 0bf4804f6e9cae872502aa4533a62ba3f6e97ee28523302deb27f9c990b5f44f
-F src/vdbe.h 73b904a6b3bb27f308c6cc287a5751ebc7f1f89456be0ed068a12b92844c6e8c
+F src/vacuum.c 4c46040e481b32cc4f24946fd5509396bd9492ecf4c1455034b03eed8533c971
+F src/vdbe.c d3b37b636d498a1feedd0484ce593cdaa0b52de1f30eadb41251646839f99e01
+F src/vdbe.h 0b42f767cef2f89db4fb4e1ff9e9a5a3e03998056bde156e64727dfb0b3814fc
 F src/vdbeInt.h a4147a4ddf613cb1bcb555ace9e9e74a9c099d65facd88155f191b1fb4d74cfb
 F src/vdbeapi.c 40c47b1528d308a322203de21d2e0d711753257ed9771771b6129214b1d65932
-F src/vdbeaux.c 3f9e3b6585e7434aa11300169dd66ddf0fc963a0c6f7940bdc058335dadeb353
-F src/vdbeblob.c 5e61ce31aca17db8fb60395407457a8c1c7fb471dde405e0cd675974611dcfcd
+F src/vdbeaux.c e5acd3dfb10472e908404aea921d6fc5a3425eb2c39cf6924b189736cd351ef9
+F src/vdbeblob.c aa23a326ff86bdde8f7ba74cf23c3e1795b13bee749314feaf26273be2f63e89
 F src/vdbemem.c 0388576b7cf0be13ce14b9e3b8aa90b8a1b923b60321d0242131ae0b5732b43b
 F src/vdbesort.c 43756031ca7430f7aec3ef904824a7883c4ede783e51f280d99b9b65c0796e35
 F src/vdbetrace.c fe0bc29ebd4e02c8bc5c1945f1d2e6be5927ec12c06d89b03ef2a4def34bf823
 F src/vdbevtab.c aae4bd769410eb7e1d02c42613eec961d514459b1c3c1c63cfc84e92a137daac
-F src/vtab.c a39f6ed161f16a84ff445af9dba4776b2cf0898be08a33bee8e1128a66c0074b
+F src/vtab.c e8d4796b1c6d5a44d213c5e6f3f9a141fc95bbab52bfa9e488bff3675019ed13
 F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c b9df133a705093da8977da5eb202eaadb844839f1c7297c08d33471f5491843d
 F src/wal.h c3aa7825bfa2fe0d85bef2db94655f99870a285778baa36307c0a16da32b226a
 F src/walker.c f890a3298418d7cba3b69b8803594fdc484ea241206a8dfa99db6dd36f8cbb3b
-F src/where.c 38c36bb654b4172148aef3b295bbbc1342b52078cf20174f771c746caa98f69a
+F src/where.c a016443c4f4853175f939dd4658e236922b14f926f06c5ee60dedeb259684bda
 F src/whereInt.h e25203e5bfee149f5f1225ae0166cfb4f1e65490c998a024249e98bb0647377c
 F src/wherecode.c b82d0d33315e1526904b95155e55e61149c4462147668e1cc4567c812735eff1
-F src/whereexpr.c a60a1f88650c561eded95c5affbe846cda71fac35033e1280f28e47934df33c8
+F src/whereexpr.c 16d1eefd95f69843b45aba6d04fe2b63fc4f51584dff85ae380f5c20718f3c75
 F src/window.c 76a27cff9ea2ded0c2c3527187029259440fabcc4cc4c07b11d942c78494a614
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/affinity2.test ce1aafc86e110685b324e9a763eab4f2a73f737842ec3b687bd965867de90627
@@ -814,7 +816,7 @@ F test/bind2.test 918bc35135f4141809ead7585909cde57d44db90a7a62aef540127148f91aa
 F test/bindxfer.test efecd12c580c14df5f4ad3b3e83c667744a4f7e0
 F test/bitvec.test 75894a880520164d73b1305c1c3f96882615e142
 F test/blob.test e7ac6c7d3a985cc4678c64f325292529a69ae252
-F test/bloom1.test 2785a190fcc2a5e170e5d38b08aca8ff0f3e3b4a74d47453d6ac1bd355180a6a
+F test/bloom1.test 80d2a16891a23fbef2a334cc7dcb6b4a60371fbaedac00aa5e3ddacac4fe3b24
 F test/boundary1.tcl 6421b2d920d8b09539503a8673339d32f7609eb1
 F test/boundary1.test 66d7f4706ccdb42d58eafdb081de07b0eb42d77b
 F test/boundary2.tcl e34ef4e930cf1083150d4d2c603e146bd3b76bcb
@@ -886,12 +888,12 @@ F test/corruptH.test 79801d97ec5c2f9f3c87739aa1ec2eb786f96454
 F test/corruptI.test a17bbf54fdde78d43cf3cc34b0057719fd4a173a3d824285b67dc5257c064c7b
 F test/corruptJ.test 4d5ccc4bf959464229a836d60142831ef76a5aa4
 F test/corruptK.test 5b4212fe346699831c5ad559a62c54e11c0611bdde1ea8423a091f9c01aa32af
-F test/corruptL.test 9d1a0055c8db19baccd12f22ac36a33ec7d63afb59e82eb30835aea8f89b94df
+F test/corruptL.test b42978028afc5eefc8b51d8d7cd6a9344ba7362d7ed4511ee2070f56e06d5a1c
 F test/corruptM.test 7d574320e08c1b36caa3e47262061f186367d593a7e305d35f15289cc2c3e067
 F test/corruptN.test 7c099d153a554001b4fb829c799b01f2ea6276cbc32479131e0db0da4efd9cc4
 F test/cost.test b11cdbf9f11ffe8ef99c9881bf390e61fe92baf2182bad1dbe6de59a7295c576
 F test/count.test cd4bd531066e8d77ef8fe1e3fc8253d042072e117ccab214b290cf83f1602249
-F test/countofview.test e17d6e6688cf74f22783c9ec6e788c0790ee4fbbaee713affd00b1ac0bb39b86
+F test/countofview.test f9025dba8a9bb673a1f3ce25405900f630f81592c226546242df1ef1e62d0192
 F test/coveridxscan.test f35c7208dedc4f98e471c569df64c0f95a49f6e072d8dc7c8f99bdee2697de1b
 F test/crash.test fb9dc4a02dcba30d4aa5c2c226f98b220b2b959f
 F test/crash2.test 5b14d4eb58b880e231361d3b609b216acda86651
@@ -924,7 +926,7 @@ F test/dbstatus.test 4a4221a883025ffd39696b3d1b3910b928fb097d77e671351acb35f3aed
 F test/dbstatus2.test f5fe0afed3fa45e57cfa70d1147606c20d2ba23feac78e9a172f2fe8ab5b78ef
 F test/decimal.test fcf403fd5585f47342234e153c4a4338cd737b8e0884ac66fc484df47dbcf1a7
 F test/default.test 9687cfb16717e4b8238c191697c98be88c0b16e568dd5368cd9284154097ef50
-F test/delete.test 31832b0c45ecb51a54348c68db173be462985901e6ed7f403d6d7a8f70ab4ef0
+F test/delete.test 2686e1c98d552ef37d79ad55b17b93fe96fad9737786917ce3839767f734c48f
 F test/delete2.test 3a03f2cca1f9a67ec469915cb8babd6485db43fa
 F test/delete3.test 555e84a00a99230b7d049d477a324a631126a6ab
 F test/delete4.test 51fafebe9503a40796d1aae1565c60524cada720e50eecac01b7fd0419d9ea0b
@@ -933,8 +935,8 @@ F test/descidx1.test edc8adee58d491b06c7157c50364eaf1c3605c9c19f8093cb1ea2b6184f
 F test/descidx2.test a0ba347037ff3b811f4c6ceca5fd0f9d5d72e74e59f2d9de346a9d2f6ad78298
 F test/descidx3.test 953c831df7ea219c73826dfbf2f6ee02d95040725aa88ccb4fa43d1a1999b926
 F test/diskfull.test 106391384780753ea6896b7b4f005d10e9866b6e
-F test/distinct.test a7687c2fb50c93f6a486936c51439a93221c6e1188f9bc7b27b3ec26f9c58b1e
-F test/distinct2.test cd1d15a4a2abf579298f7161e821ed50c0119136fe0424db85c52cf0adc230d1
+F test/distinct.test 691c9e850b0d0b56b66e7e235453198cb4cf0760e324b7403d3c5abbeab0a014
+F test/distinct2.test bb71cc7b5e58e895787f9910a788c254f679928d324732d063fe9bc202ecbe71
 F test/distinctagg.test 14ec5026e684eddd414c61c08692b43773e224ac92efbed6ec08c6994bc39723
 F test/e_blobbytes.test 4c01dfe4f12087b92b20705a3fdfded45dc4ed16d5a211fed4e1d2786ba68a52
 F test/e_blobclose.test 692fc02a058476c2222a63d97e3f3b2b809c1842e5525ded7f854d540ac2e075
@@ -1152,7 +1154,7 @@ F test/fuzzer2.test a85ef814ce071293bce1ad8dffa217cbbaad4c14
 F test/fuzzerfault.test f64c4aef4c9e9edf1d6dc0d3f1e65dcc81e67c996403c88d14f09b74807a42bc
 F test/fuzzinvariants.c a153253600b2b33a7d5710d40e89b2ac1373a1912517867fb995a45b2d67dcb8
 F test/gcfault.test dd28c228a38976d6336a3fc42d7e5f1ad060cb8c
-F test/gencol1.test cc0dbb0ee116e5602e18ea7d47f2a0f76b26e09a823b7c36ef254370c2b0f3c1
+F test/gencol1.test aef8b0670abd4b1ae4cae786b15a43758d86f6cd9f12b381d45d96bb51e597c9
 F test/genesis.tcl 1e2e2e8e5cc4058549a154ff1892fe5c9de19f98
 F test/having.test a89236dd8d55aa50c4805f82ac9daf64d477a44d712d8209c118978d0ca21ec9
 F test/hexlit.test 4a6a5f46e3c65c4bf1fa06f5dd5a9507a5627751
@@ -1215,7 +1217,7 @@ F test/ioerr5.test 2edfa4fb0f896f733071303b42224df8bedd9da4
 F test/ioerr6.test a395a6ab144b26a9e3e21059a1ab6a7149cca65b
 F test/istrue.test e7f285bb70282625c258e866ce6337d4c762922f5a300e1b50f958aef6e7d9c9
 F test/join.test e32cb9b1491eed682489e2cde33a22a4eb7611fe5aa3b0aa4b275fe27ab3f3ac
-F test/join2.test 466b07233820f5deee66a6c3bf6e4500c8bbf7b83649e67606f5f649c07928c0
+F test/join2.test 8561fe82ce434ac96de91544072e578dc2cadddf2d9bc9cd802f866a9b92502e
 F test/join3.test 6f0c774ff1ba0489e6c88a3e77b9d3528fb4fda0
 F test/join4.test 1a352e4e267114444c29266ce79e941af5885916
 F test/join5.test 91f1f4c7d81fd87b58e9ba7cf4a2b5d39e3583b4f8e498a162722a60259c5208
@@ -1333,7 +1335,7 @@ F test/notify1.test 669b2b743618efdc18ca4b02f45423d5d2304abf
 F test/notify2.test 2ecabaa1305083856b7c39cf32816b612740c161
 F test/notify3.test 796c7b7157f55c93b4e672b724e9c923a6fc6aa72ac419379a623e2350472e22
 F test/notnull.test a37b663d5bb728d66fc182016613fb8e4a0a4bbf3d75b8876a7527f7d4ed3f18
-F test/notnull2.test 8e1aa4f311df37f9d2cd4f5563eea955b8028c692151404e9cc896420a01a3dc
+F test/notnull2.test 1ee4acbd614d3cf5f1c4a52f5af7fc771b82352f1a51a86afeaa02c9df1d82ef
 F test/notnullfault.test fc4bb7845582a2b3db376001ef49118393b1b11abe0d24adb03db057ee2b73d5
 F test/null.test b7ff206a1c60fe01aa2abd33ef9ea83c93727d993ca8a613de86e925c9f2bc6f
 F test/nulls1.test 7a5e4346ee4285034100b4cd20e6784f16a9d6c927e44ecdf10034086bbee9c9
@@ -1404,8 +1406,15 @@ F test/reindex.test cd9d6021729910ece82267b4f5e1b5ac2911a7566c43b43c176a6a4732e2
 F test/releasetest_data.tcl b550dd1b122a9c969df794d05ea272df535f10ff1a245062e7ba080822378016
 F test/resetdb.test 54c06f18bc832ac6d6319e5ab23d5c8dd49fdbeec7c696d791682a8006bd5fc3
 F test/resolver01.test f4022acafda7f4d40eca94dbf16bc5fc4ac30ceb
-F test/returning1.test 3ef7b264598b3292be0cdb028e4acb7524c5fd409b33b78449f894dfd68db334
+F test/returning1.test c78efa2829d5f44165fcc7959961b298ae005d7775f09e5542bb2815bbaee692
 F test/returningfault.test ae4c4b5e8745813287a359d9ccdb9d5c883c2e68afb18fb0767937d5de5692a4
+F test/reuse1.test faa2ce5ff566d936b8a10d9e22ba2ee66a54ce89fdcf8aef561df6b15b0ff3d3
+F test/reuse2.test 025d54dcbf5bb32a869ffde4884789af2ec4a302b7dc4550dfbd16e635a3dd65
+F test/reuse3.test fa1edd6a303bbb93aa076d6579fce9d2ee2d9e1a8f4d7b613ac20a76ba622eaa
+F test/reuse4.test adaad66253aea6cc748674328abe69b650c5c78b8676ed1162d3de09742519f9
+F test/reuse5.test bbe6cf7384ef90f134392edd93d626385ef0bf6f40eefc3d993535cd0861d83b
+F test/reuse6.test f4674f9967aee2a0b49c02832120b8b495291c0d87aae084c54e6c0cc18132fe
+F test/reusefault.test ef646a0fb51d50ddfb4b7cd872f88e7d36eaba64bde7797b3418c3774e1c8d14
 F test/rollback.test 06680159bc6746d0f26276e339e3ae2f951c64812468308838e0a3362d911eaa
 F test/rollback2.test 3f3a4e20401825017df7e7671e9f31b6de5fae5620c2b9b49917f52f8c160a8f
 F test/rollbackfault.test 0e646aeab8840c399cfbfa43daab46fd609cf04a
@@ -1538,7 +1547,7 @@ F test/subquery.test 3a1a5b600b8d4f504d2a2c61f33db820983dba94a0ef3e4aedca8f0165e
 F test/subquery2.test 90cf944b9de8204569cf656028391e4af1ccc8c0cc02d4ef38ee3be8de1ffb12
 F test/subselect.test 0966aa8e720224dbd6a5e769a3ec2a723e332303
 F test/substr.test a673e3763e247e9b5e497a6cacbaf3da2bd8ec8921c0677145c109f2e633f36b
-F test/subtype1.test 45c85632abd38f7ea9b33f17448d966d67550f552e0822bab74576814d0d1718
+F test/subtype1.test 7a9c55ed84d4ce551203d18046f925e293d75f69da81bff71aaf2696e4a2a748
 F test/superlock.test ec94f0556b6488d97f71c79f9061ae08d9ab8f12
 F test/swarmvtab.test 250231404fcac88f61a6c147bb0e3a118ed879278cd3ccb0ae2d3a729e1e8e26
 F test/swarmvtab2.test c948cb2fdfc5b01d85e8f6d6504854202dc1a0782ab2a0ed61538f27cbd0aa5c
@@ -1554,7 +1563,7 @@ F test/tabfunc01.test 241425ce3998687ab24adba09cb95e8012e17499b84a0ed47e128ab45e
 F test/table.test eb3463b7add9f16a5bb836badf118cf391b809d09fdccd1f79684600d07ec132
 F test/tableapi.test ecbcc29c4ab62c1912c3717c48ea5c5e59f7d64e4a91034e6148bd2b82f177f4
 F test/tableopts.test dba698ba97251017b7c80d738c198d39ab747930
-F test/tclsqlite.test ad0bbd92edabe64cc91d990a0748142fe5ab962d74ac71fa3bfa94d50d2f4c87
+F test/tclsqlite.test 350536a4233914aa437b6735e3e8e683e921a71ced8fa9fb5396057a04dbea33
 F test/tempdb.test 4cdaa23ddd8acb4d79cbb1b68ccdfd09b0537aaba909ca69a876157c2a2cbd08
 F test/tempdb2.test 353864e96fd3ae2f70773d0ffbf8b1fe48589b02c2ec05013b540879410c3440
 F test/tempfault.test 0c0d349c9a99bf5f374655742577f8712c647900
@@ -1562,7 +1571,7 @@ F test/temptable.test d2c9b87a54147161bcd1822e30c1d1cd891e5b30
 F test/temptable2.test 76821347810ecc88203e6ef0dd6897b6036ac788e9dd3e6b04fd4d1631311a16
 F test/temptable3.test d11a0974e52b347e45ee54ef1923c91ed91e4637
 F test/temptrigger.test 38f0ca479b1822d3117069e014daabcaacefffcc
-F test/tester.tcl 8d54d40a55e12554b4509bc12078b201b233c8e842a7543629094a21b1ba956d
+F test/tester.tcl 68454ef88508c196d19e8694daa27bff7107a91857799eaa12f417188ae53ede
 F test/testrunner.tcl e0b36a732956c69ce19370611b8dc69b44e627d5ea8ec2a5455ca3e8a170ddaa
 F test/testrunner_data.tcl 8169c68654ac8906833b8a6aadca973358a441ebf88270dd05c153e5f96f76b8
 F test/thread001.test a0985c117eab62c0c65526e9fa5d1360dd1cac5b03bde223902763274ce21899
@@ -1575,7 +1584,7 @@ F test/thread2.test f35d2106452b77523b3a2b7d1dcde2e5ee8f9e46
 F test/thread_common.tcl 334639cadcb9f912bf82aa73f49efd5282e6cadd
 F test/threadtest1.c 6029d9c5567db28e6dc908a0c63099c3ba6c383b
 F test/threadtest2.c a70a8e94bef23339d34226eb9521015ef99f4df8
-F test/threadtest3.c 655bff6c0895ec03f014126aa65e808fac9aae8c5a7a7da58a510cbe8b43b781
+F test/threadtest3.c 25cb92accb4fa6d53e708d6006ed2db7a7533ef7b838ef1306455c6fe57e978a
 F test/threadtest4.c c1e67136ceb6c7ec8184e56ac61db28f96bd2925
 F test/threadtest5.c 9b4d782c58d8915d7e955ff8051f3d03628bda0d33b82971ea8c0f2f2808c421
 F test/time-wordcount.sh 8e0b0f8109367827ad5d58f5cc849705731e4b90
@@ -1612,7 +1621,7 @@ F test/tkt-868145d012.test a5f941107ece6a64410ca4755c6329b7eb57a356
 F test/tkt-8c63ff0ec.test 258b7fc8d7e4e1cb5362c7d65c143528b9c4cbed
 F test/tkt-91e2e8ba6f.test 08c4f94ae07696b05c9b822da0b4e5337a2f54c5
 F test/tkt-94c04eaadb.test f738c57c7f68ab8be1c054415af7774617cb6223
-F test/tkt-99378177930f87bd.test 2f07020a82ed1c56bdad60a8a6ef508b2f8a1fb056300b7ec650cbd9975b46bf
+F test/tkt-99378177930f87bd.test 28530bf9903dcd7743185ce78b1c02b1f9ba09fe4fa77a70ecbd0af83fe3353c
 F test/tkt-9a8b09f8e6.test b2ef151d0984b2ebf237760dbeaa50724e5a0667
 F test/tkt-9d68c883.test 16f7cb96781ba579bc2e19bb14b4ad609d9774b6
 F test/tkt-9f2eb3abac.test cb6123ac695a08b4454c3792fbe85108f67fabf8
@@ -1750,12 +1759,13 @@ F test/triggerF.test 5d76f0a8c428ff87a4d5ed52da06f6096a2c787a1e21b846111dfac4123
 F test/triggerG.test 2b816093c91ba73c733cfa8aedcc210ad819d72a98b1da30768a3c56505233e9
 F test/triggerupfrom.test d1f9e56090408115c522bee626cc33a2f3370f627a5e341d832589d72e3aa271
 F test/trustschema1.test d2996bb284859c99956ac706160eab9f086919da738d19bfef3ac431cce8fd47
-F test/tt3_checkpoint.c ac7ca661d739280c89d9c253897df64a59a49369bd1247207ac0f655b622579d
-F test/tt3_index.c 39eec10a35f57672225be4d182862152896dee4a
-F test/tt3_lookaside1.c 0377e202c3c2a50d688cb65ba203afeda6fafeb9
+F test/tt3_checkpoint.c 69214e2ce81bbbd3c1b82c31e103607fd2e6790818aef4792957fc9cc88d067e
+F test/tt3_index.c 95592839426dc85ce5a7a57b41be2cbf3c2ec3457b9cd841a06ed5877f712c7c
+F test/tt3_lookaside1.c 2ddd99bfffeef288f0786827ef68f912f6f47ce3d3184e62f05808d8e13b920e
+F test/tt3_reuseschema.c 4d52e141f89f009028d8ab0bd1f0697d0edffa94bafc1fff0f7ad4d9d9baa549
 F test/tt3_shared.c b37d22defc944a2ac4c91c927fd06c1d48cd51e2ce9d004fe868625bd2399f93
-F test/tt3_stress.c f9a769ca8b026ecc76ee93ca8c9700a5619f8e51c581107c4053ba6ac97f616f
-F test/tt3_vacuum.c 71b254cde1fc49d6c8c44efd54f4668f3e57d7b3a8f4601ade069f75a999ba39
+F test/tt3_stress.c 077e817ac1168443b075fedb44e92db84bb4dc5bd3b6fe1aba25c94ac280b231
+F test/tt3_vacuum.c 727bfda1299b18435eeba80dee8e6ff43462146d7c1e2096cc809f01db568391
 F test/types.test bf816ce73c7dfcfe26b700c19f97ef4050d194ff
 F test/types2.test 1aeb81976841a91eef292723649b5c4fe3bc3cac
 F test/types3.test 99e009491a54f4dc02c06bdbc0c5eea56ae3e25a
@@ -1769,7 +1779,7 @@ F test/unique.test 93f8b2ef5ea51b9495f8d6493429b1fd0f465264
 F test/unique2.test 3674e9f2a3f1fbbfd4772ac74b7a97090d0f77d2
 F test/unixexcl.test d936ba2b06794018e136418addd59a2354eeae97
 F test/unordered.test 0edaf3411d300693bca595897c5201421c6c5ec787990a1dfe2f7f60ae93f1e2
-F test/update.test eb7f4eb172ce270e51bb67d7867521f33a63635bb671e261bbafccaef3bd6db2
+F test/update.test 90772ede84cfc779fc3d31884a84ec4c74deb501eeb09a1c6c91c03d8e94c0d8
 F test/update2.test 67455bc61fcbcf96923c45b3bc4f87bc72be7d67575ad35f134906148c7b06d3
 F test/upfrom1.tcl 8859d9d437f03b44174c4524a7a734a391fd4526fcff65be08285dafc9dc9041
 F test/upfrom1.test 8cb06689e99cd707d884faa16da0e8eb26ff658bb01c47ddf72fadade666e6e1
@@ -1895,7 +1905,7 @@ F test/win32heap.test 10fd891266bd00af68671e702317726375e5407561d859be1aa04696f2
 F test/win32lock.test e0924eb8daac02bf80e9da88930747bd44dd9b230b7759fed927b1655b467c9c
 F test/win32longpath.test 4baffc3acb2e5188a5e3a895b2b543ed09e62f7c72d713c1feebf76222fe9976
 F test/win32nolock.test ac4f08811a562e45a5755e661f45ca85892bdbbc
-F test/window1.test 08bac934238ff66987635ea3367c5aed5b4c088c414441beaba426e68a8257c1
+F test/window1.test 5ad2f3e2aec3f2dc5cf4a66998d42a455b8ebd57ec173c0329f6b8788bcae0aa
 F test/window2.tcl 492c125fa550cda1dd3555768a2303b3effbeceee215293adf8871efc25f1476
 F test/window2.test e466a88bd626d66edc3d352d7d7e1d5531e0079b549ba44efb029d1fbff9fd3c
 F test/window3.tcl acea6e86a4324a210fd608d06741010ca83ded9fde438341cb978c49928faf03
@@ -1976,7 +1986,7 @@ F tool/mkmsvcmin.tcl 6ecab9fe22c2c8de4d82d4c46797bda3d2deac8e763885f5a38d0c44a89
 F tool/mkopcodec.tcl 33d20791e191df43209b77d37f0ff0904620b28465cca6990cf8d60da61a07ef
 F tool/mkopcodeh.tcl 769d9e6a8b462323150dc13a8539d6064664b72974f7894befe2491cc73e05cd
 F tool/mkopts.tcl 680f785fdb09729fd9ac50632413da4eadbdf9071535e3f26d03795828ab07fa
-F tool/mkpragmatab.tcl bd07bd59d45d0f3448e123d6937e9811195f9908a51e09d774609883055bfd3d
+F tool/mkpragmatab.tcl 0e059aaab521b490c86ba3d4f945319b438558de7738e90f26c54f4ffcdd79bb
 F tool/mkshellc.tcl b7adf08b82de60811d2cb6af05ff59fc17e5cd6f3e98743c14eaaa3f8971fed0
 F tool/mksourceid.c 36aa8020014aed0836fd13c51d6dc9219b0df1761d6b5f58ff5b616211b079b9
 F tool/mkspeedsql.tcl a1a334d288f7adfe6e996f2e712becf076745c97
@@ -2045,10 +2055,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 409a19145e9558686acab730b94c6d53691b6d0efcea1e9239fc7e5863586a85
-R 8cba8b939a0caa0ad935e665db07c75b
-T +sym-release *
-T +sym-version-3.41.0 *
+P af08bd3e6eff9f519ae066f9c4c010ea78edff853e190ba7f3627238b7c078c4 0d1fc92f94cb6b76bffe3ec34d69cffde2924203304e8ffc4155597af0c191da
+R 72de83c594c153d42b5b460cfd3eaca3
 U drh
-Z dc017a46fcafa54656c31865fbc11b74
+Z a51f18aac23765e80f843b6cc71deba7
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-05941c2a04037fc3ed2ffae11f5d2260706f89431f463518740f72ada350866d
+995fa4d09dd15478222eb790da7b5b1a9ffcf5d537f3faa396cd0f9b939fd739

src/alter.c

@@ -112,8 +112,8 @@ static void renameReloadSchema(Parse *pParse, int iDb, u16 p5){
   Vdbe *v = pParse->pVdbe;
   if( v ){
     sqlite3ChangeCookie(pParse, iDb);
-    sqlite3VdbeAddParseSchemaOp(pParse->pVdbe, iDb, 0, p5);
-    if( iDb!=1 ) sqlite3VdbeAddParseSchemaOp(pParse->pVdbe, 1, 0, p5);
+    sqlite3VdbeAddParseSchemaOp(pParse, iDb, 0, p5);
+    if( iDb!=1 ) sqlite3VdbeAddParseSchemaOp(pParse, 1, 0, p5);
   }
 }
 

src/analyze.c

@@ -212,6 +212,7 @@ static void openStatTable(
         ** side-effect of the CREATE TABLE statement is to leave the rootpage 
         ** of the new table in register pParse->regRoot. This is important 
         ** because the OpenWrite opcode below will be needing it. */
+        sqlite3SchemaWritable(pParse, iDb);
         sqlite3NestedParse(pParse,
             "CREATE TABLE %Q.%s(%s)", pDb->zDbSName, zTab, aTable[i].zCols
         );

src/attach.c

@@ -218,14 +218,14 @@ static void attachFunc(
   ** way we found it.
   */
   if( rc==SQLITE_OK ){
-    sqlite3BtreeEnterAll(db);
     db->init.iDb = 0;
     db->mDbFlags &= ~(DBFLAG_SchemaKnownOk);
-    if( !REOPEN_AS_MEMDB(db) ){
+    if( !IsSharedSchema(db) && !REOPEN_AS_MEMDB(db) ){
+      sqlite3BtreeEnterAll(db);
       rc = sqlite3Init(db, &zErrDyn);
+      sqlite3BtreeLeaveAll(db);
+      assert( zErrDyn==0 || rc!=SQLITE_OK );
     }
-    sqlite3BtreeLeaveAll(db);
-    assert( zErrDyn==0 || rc!=SQLITE_OK );
   }
 #ifdef SQLITE_USER_AUTHENTICATION
   if( rc==SQLITE_OK && !REOPEN_AS_MEMDB(db) ){
@@ -325,6 +325,7 @@ static void detachFunc(
     pEntry = sqliteHashNext(pEntry);
   }
 
+  (void)sqlite3SchemaDisconnect(db, i, 0);
   sqlite3BtreeClose(pDb->pBt);
   pDb->pBt = 0;
   pDb->pSchema = 0;
@@ -354,7 +355,9 @@ static void codeAttach(
   sqlite3* db = pParse->db;
   int regArgs;
 
-  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ) goto attach_end;
+  if( (db->mDbFlags & DBFLAG_EncodingFixed)==0 ){
+    if( SQLITE_OK!=sqlite3ReadSchema(pParse) ) goto attach_end;
+  }
 
   if( pParse->nErr ) goto attach_end;
   memset(&sName, 0, sizeof(NameContext));

src/btree.c

@@ -6084,7 +6084,7 @@ static SQLITE_NOINLINE int btreeNext(BtCursor *pCur){
 
   pPage = pCur->pPage;
   idx = ++pCur->ix;
-  if( NEVER(!pPage->isInit) || sqlite3FaultSim(412) ){
+  if( !pPage->isInit || sqlite3FaultSim(412) ){
     return SQLITE_CORRUPT_BKPT;
   }
 
@@ -9213,6 +9213,7 @@ int sqlite3BtreeInsert(
   assert( szNew==pPage->xCellSize(pPage, newCell) );
   assert( szNew <= MX_CELL_SIZE(p->pBt) );
   idx = pCur->ix;
+  pCur->info.nSize = 0;
   if( loc==0 ){
     CellInfo info;
     assert( idx>=0 );
@@ -9285,7 +9286,6 @@ int sqlite3BtreeInsert(
   ** larger than the largest existing key, it is possible to insert the
   ** row without seeking the cursor. This can be a big performance boost.
   */
-  pCur->info.nSize = 0;
   if( pPage->nOverflow ){
     assert( rc==SQLITE_OK );
     pCur->curFlags &= ~(BTCF_ValidNKey);

src/build.c

@@ -341,6 +341,39 @@ int sqlite3UserAuthTable(const char *zTable){
 }
 #endif
 
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+/*
+** If this database connection was opened with the SQLITE_OPEN_SHARED_SCHEMA
+** flag specified, then ensure that the database schema for database iDb
+** is loaded. Either by obtaining a Schema object from the schema-pool, or
+** by reading the contents of the sqlite_master table. Unless it is NULL, 
+** the location indicated by parameter pbUnload is set to 1 if a shared-schema 
+** is loaded.
+**
+** If the database handle was not opened with SQLITE_OPEN_SHARED_SCHEMA, or
+** if the schema for database iDb is already loaded, this function is a no-op.
+**
+** SQLITE_OK is returned if successful, or an SQLite error code otherwise. If
+** an error code is returned, (*pzErr) may be set to point to a buffer
+** containing an error message. It is the responsibility of the caller to
+** eventually free this buffer using sqlite3_free().
+*/
+int sqlite3SchemaLoad(sqlite3 *db, int iDb, int *pbUnload, char **pzErr){
+  int rc = SQLITE_OK;
+  if( IsSharedSchema(db) 
+      && DbHasProperty(db, iDb, DB_SchemaLoaded)==0 
+      && (db->init.busy==0 || (iDb!=1 && db->init.iDb==1))
+  ){
+    struct sqlite3InitInfo sv = db->init;
+    memset(&db->init, 0, sizeof(struct sqlite3InitInfo));
+    rc = sqlite3InitOne(db, iDb, pzErr, 0);
+    db->init = sv;
+    if( pbUnload && rc==SQLITE_OK && iDb!=1 ) *pbUnload = 1;
+  }
+  return rc;
+}
+#endif
+
 /*
 ** Locate the in-memory structure that describes a particular database
 ** table given the name of that table and (optionally) the name of the
@@ -366,59 +399,41 @@ Table *sqlite3FindTable(sqlite3 *db, const char *zName, const char *zDatabase){
     return 0;
   }
 #endif
-  if( zDatabase ){
-    for(i=0; i<db->nDb; i++){
-      if( sqlite3StrICmp(zDatabase, db->aDb[i].zDbSName)==0 ) break;
-    }
-    if( i>=db->nDb ){
-      /* No match against the official names.  But always match "main"
-      ** to schema 0 as a legacy fallback. */
-      if( sqlite3StrICmp(zDatabase,"main")==0 ){
-        i = 0;
-      }else{
-        return 0;
-      }
-    }
-    p = sqlite3HashFind(&db->aDb[i].pSchema->tblHash, zName);
-    if( p==0 && sqlite3StrNICmp(zName, "sqlite_", 7)==0 ){
-      if( i==1 ){
-        if( sqlite3StrICmp(zName+7, &PREFERRED_TEMP_SCHEMA_TABLE[7])==0
-         || sqlite3StrICmp(zName+7, &PREFERRED_SCHEMA_TABLE[7])==0
-         || sqlite3StrICmp(zName+7, &LEGACY_SCHEMA_TABLE[7])==0
-        ){
-          p = sqlite3HashFind(&db->aDb[1].pSchema->tblHash, 
-                              LEGACY_TEMP_SCHEMA_TABLE);
+  while(1){
+    for(i=OMIT_TEMPDB; i<db->nDb; i++){
+      int j = (i<2) ? i^1 : i;   /* Search TEMP before MAIN */
+      if( zDatabase==0 || sqlite3DbIsNamed(db, j, zDatabase) ){
+        int bUnload = 0;
+        assert( sqlite3SchemaMutexHeld(db, j, 0) );
+        if( IsSharedSchema(db) ){
+          Parse *pParse = db->pParse;
+          if( pParse && pParse->nErr==0 ){
+            pParse->rc = sqlite3SchemaLoad(db, j, &bUnload, &pParse->zErrMsg);
+            if( pParse->rc ) pParse->nErr++;
+          }
         }
-      }else{
-        if( sqlite3StrICmp(zName+7, &PREFERRED_SCHEMA_TABLE[7])==0 ){
-          p = sqlite3HashFind(&db->aDb[i].pSchema->tblHash,
-                              LEGACY_SCHEMA_TABLE);
+        p = sqlite3HashFind(&db->aDb[j].pSchema->tblHash, zName);
+        if( p ) return p;
+        if( bUnload ){
+          sqlite3SchemaRelease(db, j);
         }
       }
     }
-  }else{
-    /* Match against TEMP first */
-    p = sqlite3HashFind(&db->aDb[1].pSchema->tblHash, zName);
-    if( p ) return p;
-    /* The main database is second */
-    p = sqlite3HashFind(&db->aDb[0].pSchema->tblHash, zName);
-    if( p ) return p;
-    /* Attached databases are in order of attachment */
-    for(i=2; i<db->nDb; i++){
-      assert( sqlite3SchemaMutexHeld(db, i, 0) );
-      p = sqlite3HashFind(&db->aDb[i].pSchema->tblHash, zName);
-      if( p ) break;
+    /* Not found.  If the name we were looking for was temp.sqlite_master
+    ** then change the name to sqlite_temp_master and try again. */
+    if( sqlite3StrICmp(zName, PREFERRED_SCHEMA_TABLE)==0 ){
+      zName = LEGACY_SCHEMA_TABLE;
+      continue;
     }
-    if( p==0 && sqlite3StrNICmp(zName, "sqlite_", 7)==0 ){
-      if( sqlite3StrICmp(zName+7, &PREFERRED_SCHEMA_TABLE[7])==0 ){
-        p = sqlite3HashFind(&db->aDb[0].pSchema->tblHash, LEGACY_SCHEMA_TABLE);
-      }else if( sqlite3StrICmp(zName+7, &PREFERRED_TEMP_SCHEMA_TABLE[7])==0 ){
-        p = sqlite3HashFind(&db->aDb[1].pSchema->tblHash, 
-                            LEGACY_TEMP_SCHEMA_TABLE);
-      }
+    if( sqlite3StrICmp(zName, PREFERRED_TEMP_SCHEMA_TABLE)==0 ){
+      zName = LEGACY_TEMP_SCHEMA_TABLE;
+      continue;
     }
+    if( sqlite3StrICmp(zName, LEGACY_SCHEMA_TABLE)!=0 ) break;
+    if( sqlite3_stricmp(zDatabase, db->aDb[1].zDbSName)!=0 ) break;
+    zName = LEGACY_TEMP_SCHEMA_TABLE;
   }
-  return p;
+  return 0;
 }
 
 /*
@@ -443,6 +458,7 @@ Table *sqlite3LocateTable(
   /* Read the database schema. If an error occurs, leave an error message
   ** and code in pParse and return NULL. */
   if( (db->mDbFlags & DBFLAG_SchemaKnownOk)==0 
+   && !IsSharedSchema(db)
    && SQLITE_OK!=sqlite3ReadSchema(pParse)
   ){
     return 0;
@@ -459,9 +475,21 @@ Table *sqlite3LocateTable(
       if( pMod==0 && sqlite3_strnicmp(zName, "pragma_", 7)==0 ){
         pMod = sqlite3PragmaVtabRegister(db, zName);
       }
-      if( pMod && sqlite3VtabEponymousTableInit(pParse, pMod) ){
-        testcase( pMod->pEpoTab==0 );
-        return pMod->pEpoTab;
+      if( pMod ){
+        if( IsSharedSchema(db) && pParse->nErr==0 ){
+          int bDummy = 0;
+          pParse->rc = sqlite3SchemaLoad(db, 0, &bDummy, &pParse->zErrMsg);
+          if( pParse->rc ) pParse->nErr++;
+          (void)bDummy;
+        }
+        if( sqlite3VtabEponymousTableInit(pParse, pMod) ){
+          Table *pEpoTab = pMod->pEpoTab;
+          if( pEpoTab ){
+            assert( IsSharedSchema(db)||pEpoTab->pSchema==db->aDb[0].pSchema );
+            pEpoTab->pSchema = db->aDb[0].pSchema;  /* For SHARED_SCHEMA mode */
+          }
+          return pEpoTab;
+        }
       }
     }
 #endif
@@ -471,15 +499,13 @@ Table *sqlite3LocateTable(
     p = 0;
   }
 
-  if( p==0 ){
+  if( p==0 && (!IsSharedSchema(db) || pParse->nErr==0) ){
     const char *zMsg = flags & LOCATE_VIEW ? "no such view" : "no such table";
     if( zDbase ){
       sqlite3ErrorMsg(pParse, "%s: %s.%s", zMsg, zDbase, zName);
     }else{
       sqlite3ErrorMsg(pParse, "%s: %s", zMsg, zName);
     }
-  }else{
-    assert( HasRowid(p) || p->iPKey<0 );
   }
 
   return p;
@@ -648,11 +674,10 @@ void sqlite3ResetOneSchema(sqlite3 *db, int iDb){
     DbSetProperty(db, 1, DB_ResetWanted);
     db->mDbFlags &= ~DBFLAG_SchemaKnownOk;
   }
-
   if( db->nSchemaLock==0 ){
     for(i=0; i<db->nDb; i++){
       if( DbHasProperty(db, i, DB_ResetWanted) ){
-        sqlite3SchemaClear(db->aDb[i].pSchema);
+        sqlite3SchemaClearOrDisconnect(db, i);
       }
     }
   }
@@ -665,16 +690,17 @@ void sqlite3ResetOneSchema(sqlite3 *db, int iDb){
 void sqlite3ResetAllSchemasOfConnection(sqlite3 *db){
   int i;
   sqlite3BtreeEnterAll(db);
-  for(i=0; i<db->nDb; i++){
+  for(i=0; i<db->nDb; i=(i?i+1:2)){
     Db *pDb = &db->aDb[i];
     if( pDb->pSchema ){
       if( db->nSchemaLock==0 ){
-        sqlite3SchemaClear(pDb->pSchema);
+        sqlite3SchemaClearOrDisconnect(db, i);
       }else{
         DbSetProperty(db, i, DB_ResetWanted);
       }
     }
   }
+  sqlite3SchemaClear(db->aDb[1].pSchema);
   db->mDbFlags &= ~(DBFLAG_SchemaChange|DBFLAG_SchemaKnownOk);
   sqlite3VtabUnlockList(db);
   sqlite3BtreeLeaveAll(db);
@@ -1282,7 +1308,7 @@ void sqlite3StartTable(
   */
   if( !IN_SPECIAL_PARSE ){
     char *zDb = db->aDb[iDb].zDbSName;
-    if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
+    if( !IsSharedSchema(db) && SQLITE_OK!=sqlite3ReadSchema(pParse) ){
       goto begin_table_error;
     }
     pTable = sqlite3FindTable(db, zName, zDb);
@@ -1451,7 +1477,7 @@ void sqlite3AddReturning(Parse *pParse, ExprList *pList){
   if( pParse->pNewTrigger ){
     sqlite3ErrorMsg(pParse, "cannot use RETURNING in a trigger");
   }else{
-    assert( pParse->bReturning==0 );
+    assert( pParse->bReturning==0 || pParse->ifNotExists );
   }
   pParse->bReturning = 1;
   pRet = sqlite3DbMallocZero(db, sizeof(*pRet));
@@ -1477,7 +1503,8 @@ void sqlite3AddReturning(Parse *pParse, ExprList *pList){
   pRet->retTStep.pTrig = &pRet->retTrig;
   pRet->retTStep.pExprList = pList;
   pHash = &(db->aDb[1].pSchema->trigHash);
-  assert( sqlite3HashFind(pHash, RETURNING_TRIGGER_NAME)==0 || pParse->nErr );
+  assert( sqlite3HashFind(pHash, RETURNING_TRIGGER_NAME)==0
+          || pParse->nErr  || pParse->ifNotExists );
   if( sqlite3HashInsert(pHash, RETURNING_TRIGGER_NAME, &pRet->retTrig)
           ==&pRet->retTrig ){
     sqlite3OomFault(db);
@@ -2012,6 +2039,7 @@ void sqlite3AddGenerated(Parse *pParse, Expr *pExpr, Token *pType){
     ** turn it into one by adding a unary "+" operator. */
     pExpr = sqlite3PExpr(pParse, TK_UPLUS, pExpr, 0);
   }
+  if( pExpr && pExpr->op!=TK_RAISE ) pExpr->affExpr = pCol->affinity;
   sqlite3ColumnSetExpr(pParse, pTab, pCol, pExpr);
   pExpr = 0;
   goto generated_done;
@@ -2919,7 +2947,7 @@ void sqlite3EndTable(
 #endif
 
     /* Reparse everything to update our internal data structures */
-    sqlite3VdbeAddParseSchemaOp(v, iDb,
+    sqlite3VdbeAddParseSchemaOp(pParse, iDb,
            sqlite3MPrintf(db, "tbl_name='%q' AND type!='trigger'", p->zName),0);
   }
 
@@ -3477,7 +3505,7 @@ void sqlite3DropTable(Parse *pParse, SrcList *pName, int isView, int noErr){
   }
   assert( pParse->nErr==0 );
   assert( pName->nSrc==1 );
-  if( sqlite3ReadSchema(pParse) ) goto exit_drop_table;
+  if( !IsSharedSchema(db) && sqlite3ReadSchema(pParse) ) goto exit_drop_table;
   if( noErr ) db->suppressErr++;
   assert( isView==0 || isView==LOCATE_VIEW );
   pTab = sqlite3LocateTableItem(pParse, isView, &pName->a[0]);
@@ -3492,6 +3520,7 @@ void sqlite3DropTable(Parse *pParse, SrcList *pName, int isView, int noErr){
   }
   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
   assert( iDb>=0 && iDb<db->nDb );
+  sqlite3SchemaWritable(pParse, iDb);
 
   /* If pTab is a virtual table, call ViewGetColumnNames() to ensure
   ** it is initialized.
@@ -3946,7 +3975,7 @@ void sqlite3CreateIndex(
   if( IN_DECLARE_VTAB && idxType!=SQLITE_IDXTYPE_PRIMARYKEY ){
     goto exit_create_index;
   }
-  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
+  if( !IsSharedSchema(db) && SQLITE_OK!=sqlite3ReadSchema(pParse) ){
     goto exit_create_index;
   }
   if( sqlite3HasExplicitNulls(pParse, pList) ){
@@ -4446,7 +4475,7 @@ void sqlite3CreateIndex(
       if( pTblName ){
         sqlite3RefillIndex(pParse, pIndex, iMem);
         sqlite3ChangeCookie(pParse, iDb);
-        sqlite3VdbeAddParseSchemaOp(v, iDb,
+        sqlite3VdbeAddParseSchemaOp(pParse, iDb,
             sqlite3MPrintf(db, "name='%q' AND type='index'", pIndex->zName), 0);
         sqlite3VdbeAddOp2(v, OP_Expire, 0, 1);
       }
@@ -4596,6 +4625,7 @@ void sqlite3DropIndex(Parse *pParse, SrcList *pName, int ifExists){
     goto exit_drop_index;
   }
   iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
+  sqlite3SchemaWritable(pParse, iDb);
 #ifndef SQLITE_OMIT_AUTHORIZATION
   {
     int code = SQLITE_DROP_INDEX;

src/callback.c

@@ -16,6 +16,63 @@
 
 #include "sqliteInt.h"
 
+/*
+** Connections opened with the SQLITE_OPEN_SHARED_SCHEMA flag specified
+** may use SchemaPool objects for any database that is not the temp db
+** (iDb==1). For such databases (type "struct Db") there are three states
+** the Schema/SchemaPool object may be in.
+**
+**   1) pSPool==0, pSchema points to an empty object allocated by
+**      sqlite3_malloc(). DB_SchemaLoaded flag is clear.
+**
+**   2) pSPool!=0, pSchema points to a populated object owned by the
+**      SchemaPool. DB_SchemaLoaded flag is set.
+**
+**   3) pSPool!=0, pSchema points to the SchemaPool's static object
+**      (SchemaPool.sSchema).
+*/
+struct SchemaPool {
+  int nRef;                       /* Number of pointers to this object */
+  int nDelete;                    /* Schema objects deleted by ReleaseAll() */
+  u64 cksum;                      /* Checksum for this Schema contents */
+  Schema *pSchema;                /* Linked list of Schema objects */
+  Schema sSchema;                 /* The single dummy schema object */
+  SchemaPool *pNext;              /* Next element in schemaPoolList */
+};
+
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+#ifdef SQLITE_DEBUG
+static void assert_schema_state_ok(sqlite3 *db){
+  if( IsSharedSchema(db) && db->eOpenState!=SQLITE_STATE_ZOMBIE ){
+    int i;
+    for(i=0; i<db->nDb; i++){
+      if( i!=1 ){
+        Db *pDb = &db->aDb[i];
+        Btree *pBt = pDb->pBt;
+        if( pBt==0 ) continue;
+        assert( sqlite3BtreeSchema(pBt, 0, 0)==0 );
+        assert( pDb->pSchema );
+        if( pDb->pSPool ){
+          if( DbHasProperty(db, i, DB_SchemaLoaded)==0 ){
+            assert( pDb->pSchema->tblHash.count==0 );
+            assert( pDb->pSchema==&pDb->pSPool->sSchema );
+          }else{
+            assert( pDb->pSchema!=&pDb->pSPool->sSchema );
+          }
+        }else{
+          assert( DbHasProperty(db, i, DB_SchemaLoaded)==0 );
+          assert( pDb->pSchema->tblHash.count==0 );
+          assert( pDb->pSchema!=&pDb->pSPool->sSchema );
+        }
+      }
+    }
+  }
+}
+#else
+# define assert_schema_state_ok(x)
+#endif
+#endif /* ifdef SQLITE_ENABLE_SHARED_SCHEMA */
+
 /*
 ** Invoke the 'collation needed' callback to request a collation sequence
 ** in the encoding enc of name zName, length nName.
@@ -516,15 +573,317 @@ void sqlite3SchemaClear(void *p){
 }
 
 /*
-** Find and return the schema associated with a BTree.  Create
-** a new one if necessary.
+** If this database was opened with the SQLITE_OPEN_SHARED_SCHEMA flag
+** and iDb!=1, then disconnect from the schema-pool associated with
+** database iDb. Otherwise, clear the Schema object belonging to
+** database iDb. 
+**
+** If an OOM error occurs while disconnecting from a schema-pool, 
+** the db->mallocFailed flag is set.
+*/
+void sqlite3SchemaClearOrDisconnect(sqlite3 *db, int iDb){
+  Db *pDb = &db->aDb[iDb];
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  if( IsSharedSchema(db) && iDb!=1 && pDb->pSPool ){
+    sqlite3SchemaDisconnect(db, iDb, 1);
+  }else
+#endif
+  {
+    sqlite3SchemaClear(pDb->pSchema);
+  }
+}
+
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+/*
+** Global linked list of SchemaPool objects. Read and write access must
+** be protected by the SQLITE_MUTEX_STATIC_MASTER mutex.
+*/
+static SchemaPool *SQLITE_WSD schemaPoolList = 0;
+
+#ifdef SQLITE_TEST
+/*
+** Return a pointer to the head of the linked list of SchemaPool objects.
+** This is used by the virtual table in file test_schemapool.c.
+*/
+SchemaPool *sqlite3SchemaPoolList(void){ return schemaPoolList; }
+#endif
+
+/*
+** Database handle db was opened with the SHARED_SCHEMA flag, and database
+** iDb is currently connected to a schema-pool. When this function is called,
+** (*pnByte) is set to nInit plus the amount of memory used to store a 
+** single instance of the Schema objects managed by the schema-pool.
+** This function adjusts (*pnByte) sot hat it is set to nInit plus
+** (nSchema/nRef) of the amount of memory used by a single Schema object,
+** where nSchema is the number of Schema objects allocated by this pool,
+** and nRef is the number of connections to the schema-pool.
+*/
+void sqlite3SchemaAdjustUsed(sqlite3 *db, int iDb, int nInit, int *pnByte){
+  SchemaPool *pSPool = db->aDb[iDb].pSPool;
+  int nSchema = 0;
+  Schema *p;
+  sqlite3_mutex_enter( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) );
+  for(p=pSPool->pSchema; p; p=p->pNext){
+    nSchema++;
+  }
+  *pnByte = nInit + ((*pnByte - nInit) * nSchema) / pSPool->nRef;
+  sqlite3_mutex_leave( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) );
+}
+
+/*
+** Check that the schema of db iDb is writable (either because it is the 
+** temp db schema or because the db handle was opened without
+** SQLITE_OPEN_SHARED_SCHEMA). If so, do nothing. Otherwise, leave an 
+** error in the Parse object.
+*/
+void sqlite3SchemaWritable(Parse *pParse, int iDb){
+  if( iDb!=1 && IsSharedSchema(pParse->db) && IN_DECLARE_VTAB==0 ){
+    sqlite3ErrorMsg(pParse, "attempt to modify read-only schema");
+  }
+}
+
+/*
+** The schema object passed as the only argument was allocated using
+** sqlite3_malloc() and then populated using the usual mechanism. This
+** function frees both the Schema object and its contents.
+*/
+static void schemaDelete(Schema *pSchema){
+  sqlite3SchemaClear((void*)pSchema);
+  sqlite3_free(pSchema);
+}
+
+/*
+** When this function is called, the database connection Db must be
+** using a schema-pool (Db.pSPool!=0) and must currently have Db.pSchema
+** set to point to a populated schema object checked out from the 
+** schema-pool. It is also assumed that the STATIC_MASTER mutex is held.
+** This function returns the Schema object to the schema-pool and sets
+** Db.pSchema to point to the schema-pool's static, empty, Schema object.
+*/
+static void schemaRelease(sqlite3 *db, Db *pDb){
+  Schema *pRelease = pDb->pSchema;
+  SchemaPool *pSPool = pDb->pSPool;
+
+  assert( pDb->pSchema->iGeneration==pSPool->sSchema.iGeneration );
+  pDb->pSchema = &pSPool->sSchema;
+
+  assert( pDb->pSPool && pRelease );
+  assert( pRelease->schemaFlags & DB_SchemaLoaded );
+  assert( (pDb->pSchema->schemaFlags & DB_SchemaLoaded)==0 );
+  assert( sqlite3_mutex_held(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER)) );
+
+  /* If the DBFLAG_FreeSchema flag is set and the database connection holds
+  ** at least one other copy of the schema being released, delete it instead
+  ** of returning it to the schema-pool.  */
+  if( db->mDbFlags & DBFLAG_FreeSchema ){
+    int i;
+    for(i=0; i<db->nDb; i++){
+      Db *p = &db->aDb[i];
+      if( p!=pDb && p->pSchema!=&pSPool->sSchema && pDb->pSPool==p->pSPool ){
+        pSPool->nDelete++;
+        schemaDelete(pRelease);
+        return;
+      }
+    }
+  }
+
+  pRelease->pNext = pDb->pSPool->pSchema;
+  pDb->pSPool->pSchema = pRelease;
+}
+
+/*
+** The schema for database iDb of database handle db, which was opened
+** with SQLITE_OPEN_SHARED_SCHEMA, has just been parsed. This function either
+** finds a matching SchemaPool object on the global list (schemaPoolList) or
+** else allocates a new one and sets the Db.pSPool variable accordingly.
+**
+** SQLITE_OK is returned if no error occurs, or an SQLite error code 
+** (SQLITE_NOMEM) otherwise.
+*/
+int sqlite3SchemaConnect(sqlite3 *db, int iDb, u64 cksum){
+  Schema *pSchema = db->aDb[iDb].pSchema;
+  SchemaPool *p;
+
+  assert( pSchema && iDb!=1 && db->aDb[iDb].pSPool==0 );
+
+  sqlite3_mutex_enter( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) );
+
+  /* Search for a matching SchemaPool object */
+  for(p=schemaPoolList; p; p=p->pNext){
+    if( p->cksum==cksum && p->sSchema.schema_cookie==pSchema->schema_cookie ){
+      break;
+    }
+  }
+  if( !p ){
+    /* No SchemaPool object found. Allocate a new one. */
+    p = (SchemaPool*)sqlite3_malloc(sizeof(SchemaPool));
+    if( p ){
+      memset(p, 0, sizeof(SchemaPool));
+      p->cksum = cksum;
+      p->pNext = schemaPoolList;
+      schemaPoolList = p;
+
+      p->sSchema.schema_cookie = pSchema->schema_cookie;
+      p->sSchema.iGeneration = pSchema->iGeneration;
+      p->sSchema.file_format = pSchema->file_format;
+      p->sSchema.enc = pSchema->enc;
+      p->sSchema.cache_size = pSchema->cache_size;
+    }
+  }
+
+  if( p ) p->nRef++;
+
+  /* If the SchemaPool contains one or more free schemas at the moment, 
+  ** delete one of them. */
+  if( p && p->pSchema ){
+    Schema *pDel = p->pSchema;
+    p->pSchema = pDel->pNext;
+    schemaDelete(pDel);
+  }
+
+  sqlite3_mutex_leave( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) );
+
+  db->aDb[iDb].pSPool = p;
+  return (p ? SQLITE_OK : SQLITE_NOMEM);
+}
+
+/*
+** If parameter iDb is 1 (the temp db), or if connection handle db was not
+** opened with the SQLITE_OPEN_SHARED_SCHEMA flag, this function is a no-op.
+** Otherwise, it disconnects from the schema-pool associated with database
+** iDb, assuming it is connected.
+**
+** If parameter bNew is true, then Db.pSchema is set to point to a new, empty,
+** Schema object obtained from sqlite3_malloc(). Or, if bNew is false, then
+** Db.pSchema is set to NULL before returning.
+**
+** If the bNew parameter is true, then this function may allocate memory. 
+** If the allocation attempt fails, then SQLITE_NOMEM is returned and the
+** schema-pool is not disconnected from. Or, if no OOM error occurs, 
+** SQLITE_OK is returned.
+*/
+int sqlite3SchemaDisconnect(sqlite3 *db, int iDb, int bNew){
+  int rc = SQLITE_OK;
+  if( IsSharedSchema(db) ){
+    Db *pDb = &db->aDb[iDb];
+    SchemaPool *pSPool = pDb->pSPool;
+    assert_schema_state_ok(db);
+    assert( pDb->pSchema );
+
+    if( pSPool==0 ){
+      assert( pDb->pVTable==0 );
+      assert( bNew==0 );
+      schemaDelete(pDb->pSchema);
+      pDb->pSchema = 0;
+    }else{
+      VTable *p;
+      VTable *pNext;
+      for(p=pDb->pVTable; p; p=pNext){
+        pNext = p->pNext;
+        sqlite3VtabUnlock(p);
+      }
+      pDb->pVTable = 0;
+      sqlite3_mutex_enter( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) );
+      if( DbHasProperty(db, iDb, DB_SchemaLoaded) ){
+        schemaRelease(db, pDb);
+      }
+      if( bNew ){
+        Schema *pNew = sqlite3SchemaGet(db, 0);
+        if( pNew==0 ){
+          rc = SQLITE_NOMEM;
+        }else{
+          pDb->pSchema = pNew;
+        }
+      }
+      if( rc==SQLITE_OK ){
+        assert( pSPool->nRef>=1 );
+        pDb->pSPool = 0;
+        pSPool->nRef--;
+        if( pSPool->nRef<=0 ){
+          SchemaPool **pp;
+          while( pSPool->pSchema ){
+            Schema *pNext = pSPool->pSchema->pNext;
+            schemaDelete(pSPool->pSchema);
+            pSPool->pSchema = pNext;
+          }
+          for(pp=&schemaPoolList; (*pp)!=pSPool; pp=&((*pp)->pNext));
+          *pp = pSPool->pNext;
+          sqlite3_free(pSPool);
+        }
+      }
+      sqlite3_mutex_leave( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) );
+    }
+  }
+  return rc;
+}
+
+/*
+** Extract and return a pointer to a schema object from the SchemaPool passed
+** as the only argument, if one is available. If one is not available, return
+** NULL.
+*/
+Schema *sqlite3SchemaExtract(SchemaPool *pSPool){
+  Schema *pRet = 0;
+  sqlite3_mutex_enter( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) );
+  if( pSPool->pSchema ){
+    pRet = pSPool->pSchema;
+    pSPool->pSchema = pRet->pNext;
+    pRet->pNext = 0;
+  }
+  sqlite3_mutex_leave( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) );
+  return pRet;
+}
+
+/*
+** Return all sharable schemas held by database handle db back to their
+** respective schema-pools. Db.pSchema variables are left pointing to
+** the static, empty, Schema object owned by each schema-pool.
+*/
+void sqlite3SchemaReleaseAll(sqlite3 *db){
+  int i;
+  assert_schema_state_ok(db);
+  sqlite3_mutex_enter( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) );
+  for(i=0; i<db->nDb; i++){
+    if( i!=1 ){
+      Db *pDb = &db->aDb[i];
+      if( pDb->pSPool && DbHasProperty(db,i,DB_SchemaLoaded) ){
+        schemaRelease(db, pDb);
+      }
+    }
+  }
+  db->mDbFlags &= ~DBFLAG_FreeSchema;
+  sqlite3_mutex_leave( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) );
+}
+
+/*
+** Release any sharable schema held by connection iDb of database handle
+** db. Db.pSchema is left pointing to the static, empty, Schema object
+** owned by the schema-pool.
+*/
+void sqlite3SchemaRelease(sqlite3 *db, int iDb){
+  Db *pDb = &db->aDb[iDb];
+  assert( iDb!=1 );
+  assert_schema_state_ok(db);
+  sqlite3_mutex_enter( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) );
+  schemaRelease(db, pDb);
+  sqlite3_mutex_leave( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) );
+}
+
+#endif /* ifdef SQLITE_ENABLE_SHARED_SCHEMA */
+
+/*
+** In most cases, this function finds and returns the schema associated 
+** with BTree handle pBt, creating a new one if necessary. However, if
+** the database handle was opened with the SQLITE_OPEN_SHARED_SCHEMA flag
+** specified, a new, empty, Schema object in memory obtained by 
+** sqlite3_malloc() is always returned.
 */
 Schema *sqlite3SchemaGet(sqlite3 *db, Btree *pBt){
-  Schema * p;
-  if( pBt ){
-    p = (Schema *)sqlite3BtreeSchema(pBt, sizeof(Schema), sqlite3SchemaClear);
+  Schema *p;
+  if( pBt && IsSharedSchema(db)==0 ){
+    p = (Schema*)sqlite3BtreeSchema(pBt, sizeof(Schema), sqlite3SchemaClear);
   }else{
-    p = (Schema *)sqlite3DbMallocZero(0, sizeof(Schema));
+    p = (Schema*)sqlite3DbMallocZero(0, sizeof(Schema));
   }
   if( !p ){
     sqlite3OomFault(db);

src/ctime.c

@@ -313,6 +313,9 @@ static const char * const sqlite3azCompileOpt[] = {
 #ifdef SQLITE_ENABLE_SESSION
   "ENABLE_SESSION",
 #endif
+#if SQLITE_ENABLE_SHARED_SCHEMA
+  "ENABLE_SHARED_SCHEMA",
+#endif
 #ifdef SQLITE_ENABLE_SNAPSHOT
   "ENABLE_SNAPSHOT",
 #endif

src/delete.c

@@ -483,7 +483,7 @@ void sqlite3DeleteFrom(
 #endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
   {
     u16 wcf = WHERE_ONEPASS_DESIRED|WHERE_DUPLICATES_OK;
-    if( sNC.ncFlags & NC_VarSelect ) bComplex = 1;
+    if( sNC.ncFlags & NC_Subquery ) bComplex = 1;
     wcf |= (bComplex ? 0 : WHERE_ONEPASS_MULTIROW);
     if( HasRowid(pTab) ){
       /* For a rowid table, initialize the RowSet to an empty set */

src/expr.c

@@ -3839,9 +3839,10 @@ void sqlite3ExprCodeGeneratedColumn(
 ){
   int iAddr;
   Vdbe *v = pParse->pVdbe;
+  int nErr = pParse->nErr;
   assert( v!=0 );
   assert( pParse->iSelfTab!=0 );
-  if( pParse->iSelfTab>0 ){
+  if( pParse->iSelfTab>0 ){
     iAddr = sqlite3VdbeAddOp3(v, OP_IfNullRow, pParse->iSelfTab-1, 0, regOut);
   }else{
     iAddr = 0;
@@ -3851,6 +3852,7 @@ void sqlite3ExprCodeGeneratedColumn(
     sqlite3VdbeAddOp4(v, OP_Affinity, regOut, 1, 0, &pCol->affinity, 1);
   }
   if( iAddr ) sqlite3VdbeJumpHere(v, iAddr);
+  if( pParse->nErr>nErr ) pParse->db->errByteOffset = -1;
 }
 #endif /* SQLITE_OMIT_GENERATED_COLUMNS */
 
@@ -3867,6 +3869,7 @@ void sqlite3ExprCodeGetColumnOfTable(
   Column *pCol;
   assert( v!=0 );
   assert( pTab!=0 );
+  assert( iCol!=XN_EXPR );
   if( iCol<0 || iCol==pTab->iPKey ){
     sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
     VdbeComment((v, "%s.rowid", pTab->zName));
@@ -4133,6 +4136,7 @@ static SQLITE_NOINLINE int sqlite3IndexedExprLookup(
   IndexedExpr *p;
   Vdbe *v;
   for(p=pParse->pIdxEpr; p; p=p->pIENext){
+    u8 exprAff;
     int iDataCur = p->iDataCur;
     if( iDataCur<0 ) continue;
     if( pParse->iSelfTab ){
@@ -4140,6 +4144,16 @@ static SQLITE_NOINLINE int sqlite3IndexedExprLookup(
       iDataCur = -1;
     }
     if( sqlite3ExprCompare(0, pExpr, p->pExpr, iDataCur)!=0 ) continue;
+    assert( p->aff>=SQLITE_AFF_BLOB && p->aff<=SQLITE_AFF_NUMERIC );
+    exprAff = sqlite3ExprAffinity(pExpr);
+    if( (exprAff<=SQLITE_AFF_BLOB && p->aff!=SQLITE_AFF_BLOB)
+     || (exprAff==SQLITE_AFF_TEXT && p->aff!=SQLITE_AFF_TEXT)
+     || (exprAff>=SQLITE_AFF_NUMERIC && p->aff!=SQLITE_AFF_NUMERIC)
+    ){
+      /* Affinity mismatch on a generated column */
+      continue;
+    }
+
     v = pParse->pVdbe;
     assert( v!=0 );
     if( p->bMaybeNullRow ){
@@ -4719,10 +4733,13 @@ expr_code_doover:
       return target;
     }
     case TK_COLLATE: {
-      if( !ExprHasProperty(pExpr, EP_Collate)
-       && ALWAYS(pExpr->pLeft)
-       && pExpr->pLeft->op==TK_FUNCTION
-      ){
+      if( !ExprHasProperty(pExpr, EP_Collate) ){
+        /* A TK_COLLATE Expr node without the EP_Collate tag is a so-called
+        ** "SOFT-COLLATE" that is added to constraints that are pushed down
+        ** from outer queries into sub-queries by the push-down optimization.
+        ** Clear subtypes as subtypes may not cross a subquery boundary.
+        */
+        assert( pExpr->pLeft );
         inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
         if( inReg!=target ){
           sqlite3VdbeAddOp2(v, OP_SCopy, inReg, target);
@@ -4830,16 +4847,22 @@ expr_code_doover:
           break;
         }
       }
-      addrINR = sqlite3VdbeAddOp1(v, OP_IfNullRow, pExpr->iTable);
-      /* Temporarily disable factoring of constant expressions, since
-      ** even though expressions may appear to be constant, they are not
-      ** really constant because they originate from the right-hand side
-      ** of a LEFT JOIN. */
-      pParse->okConstFactor = 0;
+      addrINR = sqlite3VdbeAddOp3(v, OP_IfNullRow, pExpr->iTable, 0, target);
+      /* The OP_IfNullRow opcode above can overwrite the result register with
+      ** NULL.  So we have to ensure that the result register is not a value
+      ** that is suppose to be a constant.  Two defenses are needed:
+      **   (1)  Temporarily disable factoring of constant expressions
+      **   (2)  Make sure the computed value really is stored in register
+      **        "target" and not someplace else.
+      */
+      pParse->okConstFactor = 0;   /* note (1) above */
       inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
       pParse->okConstFactor = okConstFactor;
+      if( inReg!=target ){         /* note (2) above */
+        sqlite3VdbeAddOp2(v, OP_SCopy, inReg, target);
+        inReg = target;
+      }
       sqlite3VdbeJumpHere(v, addrINR);
-      sqlite3VdbeChangeP3(v, addrINR, inReg);
       break;
     }
 

src/func.c

@@ -2161,6 +2161,18 @@ static void ceilingFunc(
 static double xCeil(double x){ return ceil(x); }
 static double xFloor(double x){ return floor(x); }
 
+/*
+** Some systems do not have log2() and log10() in their standard math
+** libraries.
+*/
+#if defined(HAVE_LOG10) && HAVE_LOG10==0
+# define log10(X) (0.4342944819032517867*log(X))
+#endif
+#if defined(HAVE_LOG2) && HAVE_LOG2==0
+# define log2(X) (1.442695040888963456*log(X))
+#endif
+
+
 /*
 ** Implementation of SQL functions:
 **

src/main.c

@@ -1167,6 +1167,17 @@ static void disconnectAllVtab(sqlite3 *db){
         if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
       }
     }
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+    if( IsSharedSchema(db) && i!=1 ){
+      VTable *pVTable;
+      VTable *pNext;
+      for(pVTable=db->aDb[i].pVTable; pVTable; pVTable=pNext){
+        pNext = pVTable->pNext;
+        sqlite3VtabUnlock(pVTable);
+      }
+      db->aDb[i].pVTable = 0;
+    }
+#endif /* ifdef SQLITE_ENABLE_SHARED_SCHEMA */
   }
   for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
     Module *pMod = (Module *)sqliteHashData(p);
@@ -1335,6 +1346,7 @@ void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
       sqlite3BtreeClose(pDb->pBt);
       pDb->pBt = 0;
       if( j!=1 ){
+        (void)sqlite3SchemaDisconnect(db, j, 0);
         pDb->pSchema = 0;
       }
     }
@@ -3796,7 +3808,7 @@ int sqlite3_table_column_metadata(
   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
   int *pAutoinc               /* OUTPUT: True if column is auto-increment */
 ){
-  int rc;
+  int rc = SQLITE_OK;
   char *zErrMsg = 0;
   Table *pTab = 0;
   Column *pCol = 0;
@@ -3806,7 +3818,7 @@ int sqlite3_table_column_metadata(
   int notnull = 0;
   int primarykey = 0;
   int autoinc = 0;
-
+  int bUnlock;
 
 #ifdef SQLITE_ENABLE_API_ARMOR
   if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
@@ -3816,14 +3828,29 @@ int sqlite3_table_column_metadata(
 
   /* Ensure the database schema has been loaded */
   sqlite3_mutex_enter(db->mutex);
+  bUnlock = sqlite3LockReusableSchema(db);
   sqlite3BtreeEnterAll(db);
-  rc = sqlite3Init(db, &zErrMsg);
-  if( SQLITE_OK!=rc ){
-    goto error_out;
+  if( IsSharedSchema(db)==0 ){
+    rc = sqlite3Init(db, &zErrMsg);
   }
 
   /* Locate the table in question */
-  pTab = sqlite3FindTable(db, zTableName, zDbName);
+  if( rc==SQLITE_OK ){
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+    Parse sParse;                   /* Fake Parse object for FindTable */
+    Parse *pSaved = db->pParse;
+    memset(&sParse, 0, sizeof(sParse));
+    db->pParse = &sParse;
+#endif
+    pTab = sqlite3FindTable(db, zTableName, zDbName);
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+    sqlite3_free(sParse.zErrMsg);
+    rc = sParse.rc;
+    db->pParse = pSaved;
+#endif
+  }
+  if( SQLITE_OK!=rc ) goto error_out;
+
   if( !pTab || IsView(pTab) ){
     pTab = 0;
     goto error_out;
@@ -3896,6 +3923,7 @@ error_out:
   sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
   sqlite3DbFree(db, zErrMsg);
   rc = sqlite3ApiExit(db, rc);
+  sqlite3UnlockReusableSchema(db, bUnlock);
   sqlite3_mutex_leave(db->mutex);
   return rc;
 }

src/pcache.c

@@ -41,7 +41,7 @@
 struct PCache {
   PgHdr *pDirty, *pDirtyTail;         /* List of dirty pages in LRU order */
   PgHdr *pSynced;                     /* Last synced page in dirty page list */
-  int nRefSum;                        /* Sum of ref counts over all pages */
+  i64 nRefSum;                        /* Sum of ref counts over all pages */
   int szCache;                        /* Configured cache size */
   int szSpill;                        /* Size before spilling occurs */
   int szPage;                         /* Size of every page in this cache */
@@ -71,7 +71,7 @@ struct PCache {
     unsigned char *a;
     int j;
     pPg = (PgHdr*)pLower->pExtra;
-    printf("%3d: nRef %2d flgs %02x data ", i, pPg->nRef, pPg->flags);
+    printf("%3lld: nRef %2d flgs %02x data ", i, pPg->nRef, pPg->flags);
     a = (unsigned char *)pLower->pBuf;
     for(j=0; j<12; j++) printf("%02x", a[j]);
     printf(" ptr %p\n", pPg);
@@ -815,14 +815,14 @@ PgHdr *sqlite3PcacheDirtyList(PCache *pCache){
 ** This is not the total number of pages referenced, but the sum of the
 ** reference count for all pages.
 */
-int sqlite3PcacheRefCount(PCache *pCache){
+i64 sqlite3PcacheRefCount(PCache *pCache){
   return pCache->nRefSum;
 }
 
 /*
 ** Return the number of references to the page supplied as an argument.
 */
-int sqlite3PcachePageRefcount(PgHdr *p){
+i64 sqlite3PcachePageRefcount(PgHdr *p){
   return p->nRef;
 }
 

src/pcache.h

@@ -40,7 +40,7 @@ struct PgHdr {
   ** private to pcache.c and should not be accessed by other modules.
   ** pCache is grouped with the public elements for efficiency.
   */
-  i16 nRef;                      /* Number of users of this page */
+  i64 nRef;                      /* Number of users of this page */
   PgHdr *pDirtyNext;             /* Next element in list of dirty pages */
   PgHdr *pDirtyPrev;             /* Previous element in list of dirty pages */
                           /* NB: pDirtyNext and pDirtyPrev are undefined if the
@@ -121,12 +121,12 @@ void sqlite3PcacheClearSyncFlags(PCache *);
 void sqlite3PcacheClear(PCache*);
 
 /* Return the total number of outstanding page references */
-int sqlite3PcacheRefCount(PCache*);
+i64 sqlite3PcacheRefCount(PCache*);
 
 /* Increment the reference count of an existing page */
 void sqlite3PcacheRef(PgHdr*);
 
-int sqlite3PcachePageRefcount(PgHdr*);
+i64 sqlite3PcachePageRefcount(PgHdr*);
 
 /* Return the total number of pages stored in the cache */
 int sqlite3PcachePagecount(PCache*);

src/pragma.c

@@ -476,7 +476,13 @@ void sqlite3Pragma(
 
   /* Make sure the database schema is loaded if the pragma requires that */
   if( (pPragma->mPragFlg & PragFlg_NeedSchema)!=0 ){
-    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+    if( IsSharedSchema(db) && (zDb || (pPragma->mPragFlg & PragFlg_OneSchema)) ){
+      assert( iDb>=0 && iDb<db->nDb );
+      pParse->rc = sqlite3SchemaLoad(db, iDb, 0, &pParse->zErrMsg);
+      if( pParse->rc ) goto pragma_out;
+    }else{
+      if( sqlite3ReadSchema(pParse) ) goto pragma_out;
+    }
   }
 
   /* Register the result column names for pragmas that return results */
@@ -1987,6 +1993,23 @@ void sqlite3Pragma(
             jmp4 = integrityCheckResultRow(v);
             sqlite3VdbeJumpHere(v, jmp2);
 
+            /* The OP_IdxRowid opcode is an optimized version of OP_Column
+            ** that extracts the rowid off the end of the index record.
+            ** But it only works correctly if index record does not have
+            ** any extra bytes at the end.  Verify that this is the case. */
+            if( HasRowid(pTab) ){
+              int jmp7;
+              sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur+j, 3);
+              jmp7 = sqlite3VdbeAddOp3(v, OP_Eq, 3, 0, r1+pIdx->nColumn-1);
+              VdbeCoverage(v);
+              sqlite3VdbeLoadString(v, 3,
+                 "rowid not at end-of-record for row ");
+              sqlite3VdbeAddOp3(v, OP_Concat, 7, 3, 3);
+              sqlite3VdbeLoadString(v, 4, " of index ");
+              sqlite3VdbeGoto(v, jmp5-1);
+              sqlite3VdbeJumpHere(v, jmp7);
+            }
+
             /* Any indexed columns with non-BINARY collations must still hold
             ** the exact same text value as the table. */
             label6 = 0;
@@ -2182,9 +2205,10 @@ void sqlite3Pragma(
   ** applications for any purpose.
   */
   case PragTyp_HEADER_VALUE: {
-    int iCookie = pPragma->iArg;  /* Which cookie to read or write */
+    int iCookie;                  /* Which cookie to read or write */
+    iCookie = pPragma->iArg & PRAGMA_HEADER_VALUE_MASK;     
     sqlite3VdbeUsesBtree(v, iDb);
-    if( zRight && (pPragma->mPragFlg & PragFlg_ReadOnly)==0 ){
+    if( zRight && (pPragma->iArg & PRAGMA_HEADER_VALUE_READONLY)==0 ){
       /* Write the specified cookie value */
       static const VdbeOpList setCookie[] = {
         { OP_Transaction,    0,  1,  0},    /* 0 */

src/pragma.h

@@ -56,12 +56,19 @@
 #define PragFlg_NeedSchema 0x01 /* Force schema load before running */
 #define PragFlg_NoColumns  0x02 /* OP_ResultRow called with zero columns */
 #define PragFlg_NoColumns1 0x04 /* zero columns if RHS argument is present */
-#define PragFlg_ReadOnly   0x08 /* Read-only HEADER_VALUE */
+#define PragFlg_OneSchema  0x08 /* Only a single schema required */
 #define PragFlg_Result0    0x10 /* Acts as query when no argument */
 #define PragFlg_Result1    0x20 /* Acts as query when has one argument */
 #define PragFlg_SchemaOpt  0x40 /* Schema restricts name search if present */
 #define PragFlg_SchemaReq  0x80 /* Schema required - "main" is default */
 
+/* For PragTyp_HEADER_VALUE pragmas the Pragma.iArg value is set
+** to the index of the header field to access (always 10 or less).
+** Ored with HEADER_VALUE_READONLY if the field is read only. */
+#define PRAGMA_HEADER_VALUE_READONLY 0x0100
+#define PRAGMA_HEADER_VALUE_MASK 0x00FF
+
+
 /* Names of columns for pragmas that return multi-column result
 ** or that return single-column results where the name of the
 ** result column is different from the name of the pragma
@@ -162,7 +169,7 @@ static const PragmaName aPragmaName[] = {
 #if !defined(SQLITE_OMIT_AUTOVACUUM)
  {/* zName:     */ "auto_vacuum",
   /* ePragTyp:  */ PragTyp_AUTO_VACUUM,
-  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1|PragFlg_OneSchema,
   /* ColNames:  */ 0, 0,
   /* iArg:      */ 0 },
 #endif
@@ -183,7 +190,7 @@ static const PragmaName aPragmaName[] = {
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
  {/* zName:     */ "cache_size",
   /* ePragTyp:  */ PragTyp_CACHE_SIZE,
-  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1|PragFlg_OneSchema,
   /* ColNames:  */ 0, 0,
   /* iArg:      */ 0 },
 #endif
@@ -244,9 +251,9 @@ static const PragmaName aPragmaName[] = {
 #if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
  {/* zName:     */ "data_version",
   /* ePragTyp:  */ PragTyp_HEADER_VALUE,
-  /* ePragFlg:  */ PragFlg_ReadOnly|PragFlg_Result0,
+  /* ePragFlg:  */ PragFlg_Result0,
   /* ColNames:  */ 0, 0,
-  /* iArg:      */ BTREE_DATA_VERSION },
+  /* iArg:      */ BTREE_DATA_VERSION|PRAGMA_HEADER_VALUE_READONLY },
 #endif
 #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
  {/* zName:     */ "database_list",
@@ -258,7 +265,7 @@ static const PragmaName aPragmaName[] = {
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)
  {/* zName:     */ "default_cache_size",
   /* ePragTyp:  */ PragTyp_DEFAULT_CACHE_SIZE,
-  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1|PragFlg_OneSchema,
   /* ColNames:  */ 55, 1,
   /* iArg:      */ 0 },
 #endif
@@ -295,7 +302,7 @@ static const PragmaName aPragmaName[] = {
 #if !defined(SQLITE_OMIT_FOREIGN_KEY)
  {/* zName:     */ "foreign_key_list",
   /* ePragTyp:  */ PragTyp_FOREIGN_KEY_LIST,
-  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt|PragFlg_OneSchema,
   /* ColNames:  */ 0, 8,
   /* iArg:      */ 0 },
 #endif
@@ -311,9 +318,9 @@ static const PragmaName aPragmaName[] = {
 #if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
  {/* zName:     */ "freelist_count",
   /* ePragTyp:  */ PragTyp_HEADER_VALUE,
-  /* ePragFlg:  */ PragFlg_ReadOnly|PragFlg_Result0,
+  /* ePragFlg:  */ PragFlg_Result0,
   /* ColNames:  */ 0, 0,
-  /* iArg:      */ BTREE_FREE_PAGE_COUNT },
+  /* iArg:      */ BTREE_FREE_PAGE_COUNT|PRAGMA_HEADER_VALUE_READONLY },
 #endif
 #if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
  {/* zName:     */ "full_column_names",
@@ -353,7 +360,7 @@ static const PragmaName aPragmaName[] = {
 #if !defined(SQLITE_OMIT_AUTOVACUUM)
  {/* zName:     */ "incremental_vacuum",
   /* ePragTyp:  */ PragTyp_INCREMENTAL_VACUUM,
-  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_NoColumns,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_NoColumns|PragFlg_OneSchema,
   /* ColNames:  */ 0, 0,
   /* iArg:      */ 0 },
 #endif
@@ -384,7 +391,7 @@ static const PragmaName aPragmaName[] = {
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
  {/* zName:     */ "journal_mode",
   /* ePragTyp:  */ PragTyp_JOURNAL_MODE,
-  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_OneSchema,
   /* ColNames:  */ 0, 0,
   /* iArg:      */ 0 },
  {/* zName:     */ "journal_size_limit",
@@ -422,7 +429,7 @@ static const PragmaName aPragmaName[] = {
   /* iArg:      */ 0 },
  {/* zName:     */ "max_page_count",
   /* ePragTyp:  */ PragTyp_PAGE_COUNT,
-  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_OneSchema,
   /* ColNames:  */ 0, 0,
   /* iArg:      */ 0 },
  {/* zName:     */ "mmap_size",
@@ -450,7 +457,7 @@ static const PragmaName aPragmaName[] = {
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
  {/* zName:     */ "page_count",
   /* ePragTyp:  */ PragTyp_PAGE_COUNT,
-  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_OneSchema,
   /* ColNames:  */ 0, 0,
   /* iArg:      */ 0 },
  {/* zName:     */ "page_size",
@@ -549,14 +556,14 @@ static const PragmaName aPragmaName[] = {
 #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS) && defined(SQLITE_DEBUG)
  {/* zName:     */ "stats",
   /* ePragTyp:  */ PragTyp_STATS,
-  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_OneSchema,
   /* ColNames:  */ 33, 5,
   /* iArg:      */ 0 },
 #endif
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
  {/* zName:     */ "synchronous",
   /* ePragTyp:  */ PragTyp_SYNCHRONOUS,
-  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1|PragFlg_OneSchema,
   /* ColNames:  */ 0, 0,
   /* iArg:      */ 0 },
 #endif
@@ -645,7 +652,7 @@ static const PragmaName aPragmaName[] = {
   /* iArg:      */ 0 },
  {/* zName:     */ "wal_checkpoint",
   /* ePragTyp:  */ PragTyp_WAL_CHECKPOINT,
-  /* ePragFlg:  */ PragFlg_NeedSchema,
+  /* ePragFlg:  */ PragFlg_NeedSchema|PragFlg_OneSchema,
   /* ColNames:  */ 50, 3,
   /* iArg:      */ 0 },
 #endif

src/prepare.c

@@ -43,6 +43,11 @@ static void corruptSchema(
     pData->rc = SQLITE_ERROR;
   }else if( db->flags & SQLITE_WriteSchema ){
     pData->rc = SQLITE_CORRUPT_BKPT;
+  }else if( IsSharedSchema(db) 
+         && 0==sqlite3StrNICmp(zExtra, "malformed database schema", 17)
+  ){
+    pData->rc = SQLITE_CORRUPT_BKPT;
+    *pData->pzErrMsg = sqlite3DbStrDup(db, zExtra);
   }else{
     char *z;
     const char *zObj = azObj[1] ? azObj[1] : "?";
@@ -53,6 +58,28 @@ static void corruptSchema(
   }
 }
 
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+/*
+** Update the Schema.cksum checksum to account for the database object
+** specified by the three arguments following the first.
+*/
+static void schemaUpdateChecksum(
+  InitData *pData,                /* Schema parse context */
+  const char *zName,              /* Name of new database object */
+  const char *zRoot,              /* Root page of new database object */
+  const char *zSql                /* SQL used to create new database object */
+){
+  int i;
+  u64 cksum = pData->cksum;
+  if( zName ){
+    for(i=0; zName[i]; i++) cksum += (cksum<<3) + zName[i];
+  }
+  if( zRoot ) for(i=0; zRoot[i]; i++) cksum += (cksum<<3) + zRoot[i];
+  if( zSql ) for(i=0; zSql[i]; i++) cksum += (cksum<<3) + zSql[i];
+  pData->cksum = cksum;
+}
+#endif /* ifdef SQLITE_ENABLE_SHARED_SCHEMA */
+
 /*
 ** Check to see if any sibling index (another index on the same table)
 ** of pIndex has the same root page number, and if it does, return true.
@@ -76,6 +103,15 @@ static int sqlite3Prepare(
   sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
   const char **pzTail       /* OUT: End of parsed string */
 );
+static int sqlite3LockAndPrepare(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nBytes,               /* Length of zSql in bytes. */
+  u32 prepFlags,            /* Zero or more SQLITE_PREPARE_* flags */
+  Vdbe *pReprepare,         /* VM being reprepared */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pzTail       /* OUT: End of parsed string */
+);
 
 
 /*
@@ -141,7 +177,11 @@ int sqlite3InitCallback(void *pInit, int argc, char **argv, char **NotUsed){
     db->init.orphanTrigger = 0;
     db->init.azInit = (const char**)argv;
     pStmt = 0;
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+    TESTONLY(rcp = ) sqlite3LockAndPrepare(db, argv[4], -1, 0, 0, &pStmt, 0);
+#else
     TESTONLY(rcp = ) sqlite3Prepare(db, argv[4], -1, 0, 0, &pStmt, 0);
+#endif
     rc = db->errCode;
     assert( (rc&0xFF)==(rcp&0xFF) );
     db->init.iDb = saved_iDb;
@@ -153,7 +193,11 @@ int sqlite3InitCallback(void *pInit, int argc, char **argv, char **NotUsed){
         if( rc > pData->rc ) pData->rc = rc;
         if( rc==SQLITE_NOMEM ){
           sqlite3OomFault(db);
-        }else if( rc!=SQLITE_INTERRUPT && (rc&0xFF)!=SQLITE_LOCKED ){
+        }else if( rc!=SQLITE_INTERRUPT && (rc&0xFF)!=SQLITE_LOCKED
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+               && (rc&0xFF)!=SQLITE_IOERR
+#endif
+        ){
           corruptSchema(pData, argv, sqlite3_errmsg(db));
         }
       }
@@ -184,6 +228,12 @@ int sqlite3InitCallback(void *pInit, int argc, char **argv, char **NotUsed){
       }
     }
   }
+
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  if( IsSharedSchema(db) && iDb!=1 ){
+    schemaUpdateChecksum(pData, argv[0], argv[1], argv[2]);
+  }
+#endif
   return 0;
 }
 
@@ -211,10 +261,28 @@ int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
 
   assert( (db->mDbFlags & DBFLAG_SchemaKnownOk)==0 );
   assert( iDb>=0 && iDb<db->nDb );
-  assert( db->aDb[iDb].pSchema );
+  assert( db->aDb[iDb].pSchema || (IsSharedSchema(db) && iDb!=1) );
   assert( sqlite3_mutex_held(db->mutex) );
   assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );
 
+  pDb = &db->aDb[iDb];
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  assert( pDb->pSPool==0 || IsSharedSchema(db) );
+  if( pDb->pSPool ){
+    /* See if there is a free schema object in the schema-pool. If not,
+    ** disconnect from said schema pool and continue. This function will
+    ** connect to a (possibly different) schema-pool before returning. */
+    Schema *pNew = sqlite3SchemaExtract(pDb->pSPool);
+    if( pNew ){
+      pDb->pSchema = pNew;
+      return SQLITE_OK;
+    }
+    rc = sqlite3SchemaDisconnect(db, iDb, 1);
+    if( rc!=SQLITE_OK ) goto error_out;
+    assert( pDb->pSchema && pDb->pSPool==0 );
+  }
+#endif
+
   db->init.busy = 1;
 
   /* Construct the in-memory representation schema tables (sqlite_schema or
@@ -235,6 +303,7 @@ int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
   initData.pzErrMsg = pzErrMsg;
   initData.mInitFlags = mFlags;
   initData.nInitRow = 0;
+  initData.cksum = 0;
   initData.mxPage = 0;
   sqlite3InitCallback(&initData, 5, (char **)azArg, 0);
   db->mDbFlags &= mask;
@@ -245,7 +314,6 @@ int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
 
   /* Create a cursor to hold the database open
   */
-  pDb = &db->aDb[iDb];
   if( pDb->pBt==0 ){
     assert( iDb==1 );
     DbSetProperty(db, 1, DB_SchemaLoaded);
@@ -409,6 +477,10 @@ int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
     rc = SQLITE_OK;
   }
 
+  if( rc==SQLITE_OK && iDb!=1 && IsSharedSchema(db) ){
+    rc = sqlite3SchemaConnect(db, iDb, initData.cksum);
+  }
+
   /* Jump here for an error that occurs after successfully allocating
   ** curMain and calling sqlite3BtreeEnter(). For an error that occurs
   ** before that point, jump to error_out.
@@ -430,6 +502,35 @@ error_out:
   return rc;
 }
 
+
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+/*
+** If this is a SHARED_SCHEMA connection and the DBFLAG_SchemaInUse flag
+** is not currently set, set it and return non-zero. Otherwise, return 0.
+*/
+int sqlite3LockReusableSchema(sqlite3 *db){
+  if( IsSharedSchema(db) && (db->mDbFlags & DBFLAG_SchemaInuse)==0 ){
+    db->mDbFlags |= DBFLAG_SchemaInuse;
+    return 1;
+  }
+  return 0;
+}
+#endif /* ifdef SQLITE_ENABLE_SHARED_SCHEMA */
+
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+/*
+** This function is a no-op for non-SHARED_SCHEMA connections, or if bRelease
+** is zero. Otherwise, clear the DBFLAG_SchemaInuse flag and release all
+** schema references currently held.
+*/
+void sqlite3UnlockReusableSchema(sqlite3 *db, int bRelease){
+  if( bRelease ){
+    db->mDbFlags &= ~DBFLAG_SchemaInuse;
+    sqlite3SchemaReleaseAll(db);
+  }
+}
+#endif /* ifdef SQLITE_ENABLE_SHARED_SCHEMA */
+
 /*
 ** Initialize all database files - the main database file, the file
 ** used to store temporary tables, and any additional database files
@@ -440,8 +541,12 @@ error_out:
 ** bit is set in the flags field of the Db structure. 
 */
 int sqlite3Init(sqlite3 *db, char **pzErrMsg){
-  int i, rc;
+  int rc = SQLITE_OK;
+  int bReleaseSchema;
+  int i;
   int commit_internal = !(db->mDbFlags&DBFLAG_SchemaChange);
+
+  bReleaseSchema = sqlite3LockReusableSchema(db);
   
   assert( sqlite3_mutex_held(db->mutex) );
   assert( sqlite3BtreeHoldsMutex(db->aDb[0].pBt) );
@@ -451,20 +556,19 @@ int sqlite3Init(sqlite3 *db, char **pzErrMsg){
   /* Do the main schema first */
   if( !DbHasProperty(db, 0, DB_SchemaLoaded) ){
     rc = sqlite3InitOne(db, 0, pzErrMsg, 0);
-    if( rc ) return rc;
   }
   /* All other schemas after the main schema. The "temp" schema must be last */
-  for(i=db->nDb-1; i>0; i--){
+  for(i=db->nDb-1; rc==SQLITE_OK && i>0; i--){
     assert( i==1 || sqlite3BtreeHoldsMutex(db->aDb[i].pBt) );
     if( !DbHasProperty(db, i, DB_SchemaLoaded) ){
       rc = sqlite3InitOne(db, i, pzErrMsg, 0);
-      if( rc ) return rc;
     }
   }
-  if( commit_internal ){
+  if( rc==SQLITE_OK && commit_internal ){
     sqlite3CommitInternalChanges(db);
   }
-  return SQLITE_OK;
+  sqlite3UnlockReusableSchema(db, bReleaseSchema);
+  return rc;
 }
 
 /*
@@ -476,11 +580,12 @@ int sqlite3ReadSchema(Parse *pParse){
   sqlite3 *db = pParse->db;
   assert( sqlite3_mutex_held(db->mutex) );
   if( !db->init.busy ){
+    db->mDbFlags |= DBFLAG_FreeSchema;      /* For sharable-schema mode */
     rc = sqlite3Init(db, &pParse->zErrMsg);
     if( rc!=SQLITE_OK ){
       pParse->rc = rc;
       pParse->nErr++;
-    }else if( db->noSharedCache ){
+    }else if( db->noSharedCache && !IsSharedSchema(db) ){
       db->mDbFlags |= DBFLAG_SchemaKnownOk;
     }
   }
@@ -506,6 +611,10 @@ static void schemaIsValid(Parse *pParse){
     Btree *pBt = db->aDb[iDb].pBt;     /* Btree database to read cookie from */
     if( pBt==0 ) continue;
 
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+    if( IsSharedSchema(db) && iDb!=1 && db->aDb[iDb].pSPool==0 ) continue;
+#endif
+
     /* If there is not already a read-only (or read-write) transaction opened
     ** on the b-tree database, open one now. If a transaction is opened, it 
     ** will be closed immediately after reading the meta-value. */
@@ -835,6 +944,7 @@ static int sqlite3LockAndPrepare(
 ){
   int rc;
   int cnt = 0;
+  int bReleaseSchema = 0;
 
 #ifdef SQLITE_ENABLE_API_ARMOR
   if( ppStmt==0 ) return SQLITE_MISUSE_BKPT;
@@ -844,6 +954,7 @@ static int sqlite3LockAndPrepare(
     return SQLITE_MISUSE_BKPT;
   }
   sqlite3_mutex_enter(db->mutex);
+  bReleaseSchema = sqlite3LockReusableSchema(db);
   sqlite3BtreeEnterAll(db);
   do{
     /* Make multiple attempts to compile the SQL, until it either succeeds
@@ -854,7 +965,11 @@ static int sqlite3LockAndPrepare(
     if( rc==SQLITE_OK || db->mallocFailed ) break;
   }while( (rc==SQLITE_ERROR_RETRY && (cnt++)<SQLITE_MAX_PREPARE_RETRY)
        || (rc==SQLITE_SCHEMA && (sqlite3ResetOneSchema(db,-1), cnt++)==0) );
+
   sqlite3BtreeLeaveAll(db);
+
+  sqlite3UnlockReusableSchema(db, bReleaseSchema);
+
   rc = sqlite3ApiExit(db, rc);
   assert( (rc&db->errMask)==rc );
   db->busyHandler.nBusy = 0;

src/resolve.c

@@ -947,14 +947,10 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
       if( 0==sqlite3ExprCanBeNull(pExpr->pLeft) && !IN_RENAME_OBJECT ){
         testcase( ExprHasProperty(pExpr, EP_OuterON) );
         assert( !ExprHasProperty(pExpr, EP_IntValue) );
-        if( pExpr->op==TK_NOTNULL ){
-          pExpr->u.zToken = "true";
-          ExprSetProperty(pExpr, EP_IsTrue);
-        }else{
-          pExpr->u.zToken = "false";
-          ExprSetProperty(pExpr, EP_IsFalse);
-        }
-        pExpr->op = TK_TRUEFALSE;
+        pExpr->u.iValue = (pExpr->op==TK_NOTNULL);
+        pExpr->flags |= EP_IntValue;
+        pExpr->op = TK_INTEGER;
+
         for(i=0, p=pNC; p && i<ArraySize(anRef); p=p->pNext, i++){
           p->nRef = anRef[i];
         }
@@ -1256,8 +1252,8 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
         assert( pNC->nRef>=nRef );
         if( nRef!=pNC->nRef ){
           ExprSetProperty(pExpr, EP_VarSelect);
-          pNC->ncFlags |= NC_VarSelect;
         }
+        pNC->ncFlags |= NC_Subquery;
       }
       break;
     }

src/select.c

@@ -2332,8 +2332,6 @@ void sqlite3SubqueryColumnTypes(
     pCol->affinity = sqlite3ExprAffinity(p);
     if( pCol->affinity<=SQLITE_AFF_NONE ){
       pCol->affinity = aff;
-    }else if( pCol->affinity>=SQLITE_AFF_NUMERIC && p->op==TK_CAST ){
-      pCol->affinity = SQLITE_AFF_FLEXNUM;
     }
     if( pCol->affinity>=SQLITE_AFF_TEXT && pSelect->pNext ){
       int m = 0;
@@ -2347,6 +2345,9 @@ void sqlite3SubqueryColumnTypes(
       if( pCol->affinity>=SQLITE_AFF_NUMERIC && (m&0x02)!=0 ){
         pCol->affinity = SQLITE_AFF_BLOB;
       }
+      if( pCol->affinity>=SQLITE_AFF_NUMERIC && p->op==TK_CAST ){
+        pCol->affinity = SQLITE_AFF_FLEXNUM;
+      }
     }
     zType = columnType(&sNC, p, 0, 0, 0);
     if( zType==0 || pCol->affinity!=sqlite3AffinityType(zType, 0) ){
@@ -3861,7 +3862,9 @@ static Expr *substExpr(
         sqlite3VectorErrorMsg(pSubst->pParse, pCopy);
       }else{
         sqlite3 *db = pSubst->pParse->db;
-        if( pSubst->isOuterJoin && pCopy->op!=TK_COLUMN ){
+        if( pSubst->isOuterJoin
+         && (pCopy->op!=TK_COLUMN || pCopy->iTable!=pSubst->iNewTable)
+        ){
           memset(&ifNullRow, 0, sizeof(ifNullRow));
           ifNullRow.op = TK_IF_NULL_ROW;
           ifNullRow.pLeft = pCopy;
@@ -6377,10 +6380,12 @@ static void optimizeAggregateUseOfIndexedExpr(
   NameContext *pNC        /* Name context used to resolve agg-func args */
 ){
   assert( pAggInfo->iFirstReg==0 );
+  assert( pSelect!=0 );
+  assert( pSelect->pGroupBy!=0 );
   pAggInfo->nColumn = pAggInfo->nAccumulator;
   if( ALWAYS(pAggInfo->nSortingColumn>0) ){
     if( pAggInfo->nColumn==0 ){
-      pAggInfo->nSortingColumn = 0;
+      pAggInfo->nSortingColumn = pSelect->pGroupBy->nExpr;
     }else{
       pAggInfo->nSortingColumn =
         pAggInfo->aCol[pAggInfo->nColumn-1].iSorterColumn+1;
@@ -6805,6 +6810,7 @@ static int countOfViewOptimization(Parse *pParse, Select *p){
   if( p->pEList->nExpr!=1 ) return 0;               /* Single result column */
   if( p->pWhere ) return 0;
   if( p->pGroupBy ) return 0;
+  if( p->pOrderBy ) return 0;
   pExpr = p->pEList->a[0].pExpr;
   if( pExpr->op!=TK_AGG_FUNCTION ) return 0;        /* Result is an aggregate */
   assert( ExprUseUToken(pExpr) );
@@ -6815,7 +6821,8 @@ static int countOfViewOptimization(Parse *pParse, Select *p){
   if( ExprHasProperty(pExpr, EP_WinFunc) ) return 0;/* Not a window function */
   pSub = p->pSrc->a[0].pSelect;
   if( pSub==0 ) return 0;                           /* The FROM is a subquery */
-  if( pSub->pPrior==0 ) return 0;                   /* Must be a compound ry */
+  if( pSub->pPrior==0 ) return 0;                   /* Must be a compound */
+  if( pSub->selFlags & SF_CopyCte ) return 0;       /* Not a CTE */
   do{
     if( pSub->op!=TK_ALL && pSub->pPrior ) return 0;  /* Must be UNION ALL */
     if( pSub->pWhere ) return 0;                      /* No WHERE clause */
@@ -7258,7 +7265,6 @@ int sqlite3Select(
    && countOfViewOptimization(pParse, p)
   ){
     if( db->mallocFailed ) goto select_end;
-    pEList = p->pEList;
     pTabList = p->pSrc;
   }
 #endif

src/shell.c.in

@@ -1333,13 +1333,14 @@ static ShellState shellState;
 
 /* Allowed values for ShellState.openMode
 */
-#define SHELL_OPEN_UNSPEC      0      /* No open-mode specified */
-#define SHELL_OPEN_NORMAL      1      /* Normal database file */
-#define SHELL_OPEN_APPENDVFS   2      /* Use appendvfs */
-#define SHELL_OPEN_ZIPFILE     3      /* Use the zipfile virtual table */
-#define SHELL_OPEN_READONLY    4      /* Open a normal database read-only */
-#define SHELL_OPEN_DESERIALIZE 5      /* Open using sqlite3_deserialize() */
-#define SHELL_OPEN_HEXDB       6      /* Use "dbtotxt" output as data source */
+#define SHELL_OPEN_UNSPEC       0     /* No open-mode specified */
+#define SHELL_OPEN_NORMAL       1     /* Normal database file */
+#define SHELL_OPEN_APPENDVFS    2     /* Use appendvfs */
+#define SHELL_OPEN_ZIPFILE      3     /* Use the zipfile virtual table */
+#define SHELL_OPEN_READONLY     4     /* Open a normal database read-only */
+#define SHELL_OPEN_DESERIALIZE  5     /* Open using sqlite3_deserialize() */
+#define SHELL_OPEN_HEXDB        6     /* Use "dbtotxt" output as data source */
+#define SHELL_OPEN_SHAREDSCHEMA 7     /* Open for schema reuse */
 
 /* Allowed values for ShellState.eTraceType
 */
@@ -2774,6 +2775,7 @@ static char *shell_error_context(const char *zSql, sqlite3 *db){
   if( db==0
    || zSql==0
    || (iOffset = sqlite3_error_offset(db))<0
+   || iOffset>=strlen(zSql)
   ){
     return sqlite3_mprintf("");
   }
@@ -4749,6 +4751,12 @@ static const char *(azHelp[]) = {
   "      --sha3-384            Use the sha3-384 algorithm",
   "      --sha3-512            Use the sha3-512 algorithm",
   "    Any other argument is a LIKE pattern for tables to hash",
+#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_ENABLE_DBPAGE_VTAB)
+  ".shared-schema CMD DB1 DB2 ...",
+  "    Commands:",
+  "       check                Determine if DB1, DB2, etc have identical schemas",
+  "       fix                  Attempt to make DB1, DB2, etc compatible",
+#endif
 #if !defined(SQLITE_NOHAVE_SYSTEM) && !defined(SQLITE_SHELL_FIDDLE)
   ".shell CMD ARGS...       Run CMD ARGS... in a system shell",
 #endif
@@ -5290,6 +5298,11 @@ static void open_db(ShellState *p, int openFlags){
             SQLITE_OPEN_READONLY|p->openFlags, 0);
         break;
       }
+      case SHELL_OPEN_SHAREDSCHEMA: {
+        sqlite3_open_v2(p->pAuxDb->zDbFilename, &p->db,
+          SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_SHARED_SCHEMA,0);
+        break;
+      }
       case SHELL_OPEN_UNSPEC:
       case SHELL_OPEN_NORMAL: {
         sqlite3_open_v2(zDbFilename, &p->db,
@@ -7518,8 +7531,277 @@ end_ar_command:
 *******************************************************************************/
 #endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_HAVE_ZLIB) */
 
-#if SQLITE_SHELL_HAVE_RECOVER
+/*
+** If (*pRc) is not SQLITE_OK when this function is called, it is a no-op.
+** Otherwise, the SQL statement or statements in zSql are executed using
+** database connection db and the error code written to *pRc before
+** this function returns.
+*/
+static void shellExec(sqlite3 *db, int *pRc, const char *zSql){
+  int rc = *pRc;
+  if( rc==SQLITE_OK ){
+    char *zErr = 0;
+    rc = sqlite3_exec(db, zSql, 0, 0, &zErr);
+    if( rc!=SQLITE_OK ){
+      raw_printf(stderr, "SQL error: %s\n", zErr);
+    }
+    sqlite3_free(zErr);
+    *pRc = rc;
+  }
+}
 
+/*
+** Like shellExec(), except that zFmt is a printf() style format string.
+*/
+static void shellExecPrintf(sqlite3 *db, int *pRc, const char *zFmt, ...){
+  char *z = 0;
+  if( *pRc==SQLITE_OK ){
+    va_list ap;
+    va_start(ap, zFmt);
+    z = sqlite3_vmprintf(zFmt, ap);
+    va_end(ap);
+    if( z==0 ){
+      *pRc = SQLITE_NOMEM;
+    }else{
+      shellExec(db, pRc, z);
+    }
+    sqlite3_free(z);
+  }
+}
+
+static int sharedSchemaFix(ShellState *pState, const char *zDb){
+  int rc = SQLITE_OK;
+  i64 iLast = 0;
+  int iCookie = 0;
+  int iAutoVacuum = 0;
+  sqlite3_stmt *pStmt = 0;
+
+  shellExecPrintf(pState->db, &rc, "ATTACH '%q' AS _shared_schema_tmp", zDb);
+  shellExecPrintf(pState->db, &rc, "PRAGMA writable_schema = 1");
+  shellExecPrintf(pState->db, &rc, "BEGIN");
+  shellPreparePrintf(pState->db, &rc, &pStmt, 
+      "SELECT max(rowid) FROM _shared_schema_tmp.sqlite_master"
+  );
+  sqlite3_step(pStmt);
+  iLast = sqlite3_column_int64(pStmt, 0);
+  shellFinalize(&rc, pStmt);
+  shellPreparePrintf(pState->db, &rc, &pStmt,
+      "INSERT INTO _shared_schema_tmp.sqlite_master SELECT "
+      "  type, name, tbl_name, ("
+      "    SELECT rootpage FROM _shared_schema_tmp.sqlite_master WHERE "
+      "      type IS o.type AND name IS o.name AND rowid<=?"
+      "  ), sql FROM main.sqlite_master AS o"
+  );
+  sqlite3_bind_int64(pStmt, 1, iLast);
+  sqlite3_step(pStmt);
+  shellFinalize(&rc, pStmt);
+
+  shellExecPrintf(pState->db, &rc,
+      "DELETE FROM _shared_schema_tmp.sqlite_master WHERE rowid<=%lld",
+      iLast
+  );
+  shellExecPrintf(pState->db, &rc, "COMMIT");
+  sqlite3_exec(pState->db, "PRAGMA writable_schema = 0", 0, 0, 0);
+
+  /* Copy the auto-vacuum setting from main to the target db */
+  shellPreparePrintf(pState->db, &rc, &pStmt, "PRAGMA main.auto_vacuum");
+  sqlite3_step(pStmt);
+  iAutoVacuum = sqlite3_column_int(pStmt, 0);
+  shellFinalize(&rc, pStmt);
+  shellExecPrintf(pState->db, &rc, 
+      "PRAGMA _shared_schema_tmp.auto_vacuum = %d", iAutoVacuum
+  );
+
+  /* Vacuum the db in order to standardize the rootpage numbers. */
+  shellExecPrintf(pState->db, &rc, "VACUUM _shared_schema_tmp");
+
+  /* Set the schema-cookie value to the same as database "main" */
+  shellPreparePrintf(pState->db, &rc, &pStmt, "PRAGMA main.schema_version");
+  sqlite3_step(pStmt);
+  iCookie = sqlite3_column_int(pStmt, 0);
+  shellFinalize(&rc, pStmt);
+  shellExecPrintf(pState->db, &rc, 
+      "PRAGMA _shared_schema_tmp.schema_version = %d", iCookie
+  );
+
+  sqlite3_exec(pState->db, "DETACH _shared_schema_tmp", 0, 0, 0);
+  return rc;
+}
+
+static int sharedSchemaCheck(ShellState *pState, const char *zDb, int *peFix){
+  int rc = SQLITE_OK;
+  int bFailed = 0;
+  sqlite3_stmt *pStmt = 0;
+
+  if( peFix ) *peFix = 0;
+  shellExecPrintf(pState->db, &rc, "ATTACH '%q' AS _shared_schema_tmp", zDb);
+
+  /* Check if this database has the same set of objects as the current db */
+  shellPreparePrintf(pState->db, &rc, &pStmt, 
+    "SELECT type, name FROM _shared_schema_tmp.sqlite_master AS o "
+    "WHERE NOT EXISTS ("
+    "  SELECT 1 FROM main.sqlite_master "
+    "    WHERE name IS o.name AND type IS o.type"
+    ")"
+    " UNION ALL "
+    "SELECT type, name FROM main.sqlite_master AS o "
+    "WHERE NOT EXISTS ("
+    "  SELECT 1 FROM _shared_schema_tmp.sqlite_master "
+    "    WHERE name IS o.name AND type IS o.type"
+    ")"
+  );
+  if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+    utf8_printf(pState->out, "%s is NOT compatible (objects)\n", zDb);
+    bFailed = 1;
+  }
+  shellFinalize(&rc, pStmt);
+
+  /* Check if this database has the same set of SQL statements as the 
+  ** current db. */
+  if( bFailed==0 ){
+    shellPreparePrintf(pState->db, &rc, &pStmt, 
+        "SELECT 1 FROM _shared_schema_tmp.sqlite_master AS o "
+        "WHERE sql IS NOT ("
+        "  SELECT sql FROM main.sqlite_master "
+        "    WHERE name IS o.name AND type IS o.type"
+        ")"
+    );
+    if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+      utf8_printf(pState->out, "%s is NOT compatible (SQL)\n", zDb);
+      bFailed = 1;
+    }
+    shellFinalize(&rc, pStmt);
+  }
+
+  /* Check if this database has the same set of root pages as the current 
+  ** db. */
+  if( bFailed==0 ){
+    shellPreparePrintf(pState->db, &rc, &pStmt, 
+        "SELECT 1 FROM _shared_schema_tmp.sqlite_master AS o "
+        "WHERE rootpage IS NOT ("
+        "  SELECT rootpage FROM main.sqlite_master "
+        "    WHERE name IS o.name AND type IS o.type"
+        ")"
+    );
+    if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+      if( peFix==0 ){
+        utf8_printf(pState->out, "%s is NOT compatible (root pages)\n", zDb);
+      }
+      bFailed = 1;
+      if( peFix ) *peFix = 1;
+    }
+    shellFinalize(&rc, pStmt);
+  }
+
+  if( bFailed==0 ){
+    shellPreparePrintf(pState->db, &rc, &pStmt, 
+        "SELECT 1 WHERE ("
+        "  SELECT group_concat(rootpage || '.' || name || '.' || sql, '.') "
+        "  FROM _shared_schema_tmp.sqlite_master"
+        ") IS NOT ("
+        "  SELECT group_concat(rootpage || '.' || name || '.' || sql, '.') "
+        "  FROM main.sqlite_master"
+        ")"
+    );
+    if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+      if( peFix==0 ){
+        utf8_printf(pState->out, 
+            "%s is NOT compatible (order of sqlite_master rows)\n", zDb
+        );
+      }
+      bFailed = 1;
+      if( peFix ) *peFix = 2;
+    }
+    shellFinalize(&rc, pStmt);
+  }
+
+  if( bFailed==0 ){
+    int iMain = -1;
+    int iNew = +1;
+    shellPreparePrintf(pState->db, &rc, &pStmt, 
+        "PRAGMA main.schema_version"
+    );
+    if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+      iMain = sqlite3_column_int(pStmt, 0);
+    }
+    shellFinalize(&rc, pStmt);
+    shellPreparePrintf(pState->db, &rc, &pStmt, 
+        "PRAGMA _shared_schema_tmp.schema_version"
+    );
+    if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){
+      iNew = sqlite3_column_int(pStmt, 0);
+    }
+    shellFinalize(&rc, pStmt);
+    if( rc==SQLITE_OK && iMain!=iNew ){
+      if( peFix==0 ){
+        utf8_printf(pState->out, 
+            "%s is NOT compatible (schema cookie)\n", zDb
+        );
+      }
+      bFailed = 1;
+      if( peFix ) *peFix = 3;
+    }
+  }
+
+  if( rc==SQLITE_OK && bFailed==0 ){
+    utf8_printf(pState->out, "%s is compatible\n", zDb);
+  }
+
+  sqlite3_exec(pState->db, "DETACH _shared_schema_tmp", 0, 0, 0);
+  return rc;
+}
+
+/*
+** .shared-schema check|fix DB1 DB2...
+*/
+static int sharedSchemaDotCommand(
+  ShellState *pState,             /* Current shell tool state */
+  char **azArg,                   /* Array of arguments passed to dot command */
+  int nArg                        /* Number of entries in azArg[] */
+){
+  int rc = SQLITE_OK;
+  int bFix = 0;                   /* Fix databases if possible */
+  int n1;
+  int i;
+  if( nArg<3 ){
+    goto shared_schema_usage;
+  }
+
+  n1 = (int)strlen(azArg[1]);
+  if( n1>0 && n1<=3 && memcmp("fix", azArg[1], n1)==0 ){
+    bFix = 1;
+  }else if( n1==0 || n1>5 || memcmp("check", azArg[1], n1) ){
+    goto shared_schema_usage;
+  }
+
+  for(i=2; rc==SQLITE_OK && i<nArg; i++){
+    int eFix = 0;
+    rc = sharedSchemaCheck(pState, azArg[i], bFix ? &eFix : 0);
+    if( rc==SQLITE_OK && bFix && eFix ){
+      utf8_printf(pState->out, "Fixing %s... ", azArg[i]);
+      fflush(pState->out);
+      rc = sharedSchemaFix(pState, azArg[i]);
+      if( rc==SQLITE_OK ){
+        rc = sharedSchemaCheck(pState, azArg[i], &eFix);
+        if( rc==SQLITE_OK && eFix ){
+          utf8_printf(pState->out, "VACUUMing main... ");
+          fflush(pState->out);
+          rc = sqlite3_exec(pState->db, "VACUUM main", 0, 0, 0);
+          if( rc==SQLITE_OK ){
+            rc = sharedSchemaCheck(pState, azArg[i], 0);
+          }
+        }
+      }
+    }
+  }
+
+  return rc;
+ shared_schema_usage:
+  raw_printf(stderr, "usage: .shared-schema check|fix DB1 DB2...\n");
+  return SQLITE_ERROR;
+}
+
+#if SQLITE_SHELL_HAVE_RECOVER
 /*
 ** This function is used as a callback by the recover extension. Simply
 ** print the supplied SQL statement to stdout.
@@ -10438,6 +10720,13 @@ static int do_meta_command(char *zLine, ShellState *p){
     sqlite3_free(zSql);
   }else
 
+#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_ENABLE_DBPAGE_VTAB)
+  if( c=='s' && strncmp(azArg[0], "shared-schema", n)==0 ){
+    open_db(p, 0);
+    sharedSchemaDotCommand(p, azArg, nArg);
+  }else
+#endif
+
 #if !defined(SQLITE_NOHAVE_SYSTEM) && !defined(SQLITE_SHELL_FIDDLE)
   if( c=='s'
    && (cli_strncmp(azArg[0], "shell", n)==0
@@ -12031,6 +12320,8 @@ int SQLITE_CDECL wmain(int argc, wchar_t **wargv){
 #endif
     }else if( cli_strcmp(z,"-readonly")==0 ){
       data.openMode = SHELL_OPEN_READONLY;
+    }else if( strcmp(z,"-sharedschema")==0 ){
+      data.openMode = SHELL_OPEN_SHAREDSCHEMA;
     }else if( cli_strcmp(z,"-nofollow")==0 ){
       data.openFlags = SQLITE_OPEN_NOFOLLOW;
 #if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_HAVE_ZLIB)
@@ -12155,6 +12446,8 @@ int SQLITE_CDECL wmain(int argc, wchar_t **wargv){
 #endif
     }else if( cli_strcmp(z,"-readonly")==0 ){
       data.openMode = SHELL_OPEN_READONLY;
+    }else if( strcmp(z,"-sharedschema")==0 ){
+      data.openMode = SHELL_OPEN_SHAREDSCHEMA;
     }else if( cli_strcmp(z,"-nofollow")==0 ){
       data.openFlags |= SQLITE_OPEN_NOFOLLOW;
     }else if( cli_strcmp(z,"-ascii")==0 ){

src/sqlite.h.in

@@ -613,10 +613,11 @@ int sqlite3_exec(
 #define SQLITE_OPEN_EXRESCODE        0x02000000  /* Extended result codes */
 
 /* Reserved:                         0x00F00000 */
+#define SQLITE_OPEN_SHARED_SCHEMA    0x01000000  /* Ok for sqlite3_open_v2() */
+
 /* Legacy compatibility: */
 #define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
 
-
 /*
 ** CAPI3REF: Device Characteristics
 **

src/sqliteInt.h

@@ -1228,6 +1228,7 @@ typedef struct CteUse CteUse;
 typedef struct Db Db;
 typedef struct DbFixer DbFixer;
 typedef struct Schema Schema;
+typedef struct SchemaPool SchemaPool;
 typedef struct Expr Expr;
 typedef struct ExprList ExprList;
 typedef struct FKey FKey;
@@ -1368,6 +1369,10 @@ struct Db {
   u8 safety_level;     /* How aggressive at syncing data to disk */
   u8 bSyncSet;         /* True if "PRAGMA synchronous=N" has been run */
   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  SchemaPool *pSPool;  /* For REUSE_SCHEMA mode */
+  VTable *pVTable;     /* List of all VTable objects (REUSE_SCHEMA mode only) */
+#endif
 };
 
 /*
@@ -1399,6 +1404,9 @@ struct Schema {
   u8 enc;              /* Text encoding used by this database */
   u16 schemaFlags;     /* Flags associated with this schema */
   int cache_size;      /* Number of pages to use in the cache */
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  Schema *pNext;       /* Next Schema object SchemaPool (REUSE_SCHEMA) */
+#endif
 };
 
 /*
@@ -1724,6 +1732,12 @@ struct sqlite3 {
 #endif
 };
 
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+# define IsSharedSchema(db) (((db)->openFlags & SQLITE_OPEN_SHARED_SCHEMA)!=0)
+#else
+# define IsSharedSchema(db) 0
+#endif
+
 /*
 ** A macro to discover the encoding of a database.
 */
@@ -1805,6 +1819,9 @@ struct sqlite3 {
 #define DBFLAG_InternalFunc   0x0020  /* Allow use of internal functions */
 #define DBFLAG_EncodingFixed  0x0040  /* No longer possible to change enc. */
 
+#define DBFLAG_SchemaInuse    0x0080  /* Do not release sharable schemas */
+#define DBFLAG_FreeSchema     0x0100  /* Free extra shared schemas on release */
+
 /*
 ** Bits of the sqlite3.dbOptFlags field that are used by the
 ** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface to
@@ -2313,6 +2330,9 @@ struct VTable {
   u8 eVtabRisk;             /* Riskiness of allowing hacker access */
   int iSavepoint;           /* Depth of the SAVEPOINT stack */
   VTable *pNext;            /* Next in linked list (see above) */
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  char *zName;              /* Table name (REUSE_SCHEMA mode) */
+#endif
 };
 
 /* Allowed values for VTable.eVtabRisk
@@ -3341,7 +3361,7 @@ struct NameContext {
 #define NC_HasAgg    0x000010 /* One or more aggregate functions seen */
 #define NC_IdxExpr   0x000020 /* True if resolving columns of CREATE INDEX */
 #define NC_SelfRef   0x00002e /* Combo: PartIdx, isCheck, GenCol, and IdxExpr */
-#define NC_VarSelect 0x000040 /* A correlated subquery has been seen */
+#define NC_Subquery  0x000040 /* A subquery has been seen */
 #define NC_UEList    0x000080 /* True if uNC.pEList is used */
 #define NC_UAggInfo  0x000100 /* True if uNC.pAggInfo is used */
 #define NC_UUpsert   0x000200 /* True if uNC.pUpsert is used */
@@ -3660,6 +3680,7 @@ struct IndexedExpr {
   int iIdxCur;            /* The index cursor */
   int iIdxCol;            /* The index column that contains value of pExpr */
   u8 bMaybeNullRow;       /* True if we need an OP_IfNullRow check */
+  u8 aff;                 /* Affinity of the pExpr expression */
   IndexedExpr *pIENext;   /* Next in a list of all indexed expressions */
 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
   const char *zIdxName;   /* Name of index, used only for bytecode comments */
@@ -3711,6 +3732,9 @@ struct Parse {
   u8 withinRJSubrtn;   /* Nesting level for RIGHT JOIN body subroutines */
 #if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
   u8 earlyCleanup;     /* OOM inside sqlite3ParserAddCleanup() */
+#endif
+#ifdef SQLITE_DEBUG
+  u8 ifNotExists;      /* Might be true if IF NOT EXISTS.  Assert()s only */
 #endif
   int nRangeReg;       /* Size of the temporary register block */
   int iRangeReg;       /* First register in temporary register block */
@@ -3912,6 +3936,9 @@ struct Trigger {
   Schema *pTabSchema;     /* Schema containing the table */
   TriggerStep *step_list; /* Link list of trigger program steps             */
   Trigger *pNext;         /* Next trigger associated with the table */
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  char *zTabSchema;       /* Temp triggers in IsSharedSchema() dbs only */
+#endif
 };
 
 /*
@@ -4028,6 +4055,7 @@ typedef struct {
   int rc;             /* Result code stored here */
   u32 mInitFlags;     /* Flags controlling error messages */
   u32 nInitRow;       /* Number of rows processed */
+  u64 cksum;          /* Schema checksum for REUSE_SCHEMA mode */
   Pgno mxPage;        /* Maximum page number.  0 for no limit. */
 } InitData;
 
@@ -5188,6 +5216,29 @@ void sqlite3DefaultRowEst(Index*);
 void sqlite3RegisterLikeFunctions(sqlite3*, int);
 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
 void sqlite3SchemaClear(void *);
+void sqlite3SchemaClearOrDisconnect(sqlite3*, int);
+
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA 
+int sqlite3SchemaConnect(sqlite3*, int, u64);
+int sqlite3SchemaDisconnect(sqlite3 *, int, int);
+Schema *sqlite3SchemaExtract(SchemaPool*);
+int sqlite3SchemaLoad(sqlite3*, int, int*, char**);
+void sqlite3SchemaReleaseAll(sqlite3*);
+void sqlite3SchemaRelease(sqlite3*, int);
+void sqlite3SchemaAdjustUsed(sqlite3*, int, int, int*);
+void sqlite3SchemaWritable(Parse*, int);
+void sqlite3UnlockReusableSchema(sqlite3 *db, int bRelease);
+int sqlite3LockReusableSchema(sqlite3 *db);
+#else
+# define sqlite3SchemaWritable(x,y)
+# define sqlite3UnlockReusableSchema(x,y) (void)(y)
+# define sqlite3LockReusableSchema(x) 0
+# define sqlite3SchemaDisconnect(x,y,z) SQLITE_OK
+# define sqlite3SchemaLoad(w,x,y,z) SQLITE_OK
+# define sqlite3SchemaRelease(y,z)
+# define sqlite3SchemaConnect(x,y,z) SQLITE_OK
+#endif
+
 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
 KeyInfo *sqlite3KeyInfoAlloc(sqlite3*,int,int);

src/status.c

@@ -288,13 +288,26 @@ int sqlite3_db_status(
     case SQLITE_DBSTATUS_SCHEMA_USED: {
       int i;                      /* Used to iterate through schemas */
       int nByte = 0;              /* Used to accumulate return value */
+      int bReleaseSchema;
 
       sqlite3BtreeEnterAll(db);
+      bReleaseSchema = sqlite3LockReusableSchema(db);
       db->pnBytesFreed = &nByte;
       assert( db->lookaside.pEnd==db->lookaside.pTrueEnd );
       db->lookaside.pEnd = db->lookaside.pStart;
       for(i=0; i<db->nDb; i++){
-        Schema *pSchema = db->aDb[i].pSchema;
+        Schema *pSchema;
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+        int bUnload = 0;
+        int nUsed = nByte;
+        if( db->aDb[i].pSPool ){
+          char *zDummy = 0;
+          rc = sqlite3SchemaLoad(db, i, &bUnload, &zDummy);
+          sqlite3_free(zDummy);
+          if( rc ) break;
+        }
+#endif /* ifdef SQLITE_ENABLE_SHARED_SCHEMA */
+        pSchema = db->aDb[i].pSchema;
         if( ALWAYS(pSchema!=0) ){
           HashElem *p;
 
@@ -316,7 +329,14 @@ int sqlite3_db_status(
             sqlite3DeleteTable(db, (Table *)sqliteHashData(p));
           }
         }
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+        if( db->aDb[i].pSPool ){
+          if( bUnload ) sqlite3SchemaRelease(db, i);
+          sqlite3SchemaAdjustUsed(db, i, nUsed, &nByte);
+        }
+#endif /* ifdef SQLITE_ENABLE_SHARED_SCHEMA */
       }
+      sqlite3UnlockReusableSchema(db, bReleaseSchema);
       db->pnBytesFreed = 0;
       db->lookaside.pEnd = db->lookaside.pTrueEnd;
       sqlite3BtreeLeaveAll(db);

src/tclsqlite.c

@@ -3708,6 +3708,9 @@ static int sqliteCmdUsage(
     "HANDLE ?FILENAME? ?-vfs VFSNAME? ?-readonly BOOLEAN? ?-create BOOLEAN?"
     " ?-nofollow BOOLEAN?"
     " ?-nomutex BOOLEAN? ?-fullmutex BOOLEAN? ?-uri BOOLEAN?"
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+    " ?-shared-schema BOOLEAN?"
+#endif
   );
   return TCL_ERROR;
 }
@@ -3839,6 +3842,16 @@ static int SQLITE_TCLAPI DbMain(
       }else{
         flags &= ~SQLITE_OPEN_URI;
       }
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+    }else if( strcmp(zArg, "-shared-schema")==0 ){
+      int b;
+      if( Tcl_GetBooleanFromObj(interp, objv[i], &b) ) return TCL_ERROR;
+      if( b ){
+        flags |= SQLITE_OPEN_SHARED_SCHEMA;
+      }else{
+        flags &= ~SQLITE_OPEN_SHARED_SCHEMA;
+      }
+#endif /* ifdef SQLITE_ENABLE_SHARED_SCHEMA */
     }else if( strcmp(zArg, "-translatefilename")==0 ){
       if( Tcl_GetBooleanFromObj(interp, objv[i], &bTranslateFileName) ){
         return TCL_ERROR;

src/test_config.c

@@ -783,6 +783,12 @@ Tcl_SetVar2(interp, "sqlite_options", "mergesort", "1", TCL_GLOBAL_ONLY);
   Tcl_SetVar2(interp, "sqlite_options", "windowfunc", "1", TCL_GLOBAL_ONLY);
 #endif
 
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  Tcl_SetVar2(interp, "sqlite_options", "sharedschema", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "sharedschema", "0", TCL_GLOBAL_ONLY);
+#endif
+
 #define LINKVAR(x) { \
     static const int cv_ ## x = SQLITE_ ## x; \
     Tcl_LinkVar(interp, "SQLITE_" #x, (char *)&(cv_ ## x), \

src/test_schemapool.c

@@ -0,0 +1,282 @@
+/*
+** 2006 June 10
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Code for testing the virtual table interfaces.  This code
+** is not included in the SQLite library.  It is used for automated
+** testing of the SQLite library.
+*/
+
+/*
+** None of this works unless we have virtual tables.
+*/
+#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_TEST)
+
+#include <tcl.h>
+
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+
+#include "sqliteInt.h"
+
+/* The code in this file defines a sqlite3 virtual-table module with
+** the following schema.
+*/
+#define SCHEMAPOOL_SCHEMA \
+"CREATE TABLE x("         \
+"  cksum   INTEGER, "     \
+"  nref    INTEGER, "     \
+"  nschema INTEGER, "     \
+"  ndelete INTEGER  "     \
+")"
+
+#define SCHEMAPOOL_NFIELD 4
+
+typedef struct schemapool_vtab schemapool_vtab;
+typedef struct schemapool_cursor schemapool_cursor;
+
+/* A schema table object */
+struct schemapool_vtab {
+  sqlite3_vtab base;
+};
+
+/* A schema table cursor object */
+struct schemapool_cursor {
+  sqlite3_vtab_cursor base;
+  sqlite3_int64 *aData;
+  int iRow;
+  int nRow;
+};
+
+/*
+** Table destructor for the schema module.
+*/
+static int schemaPoolDestroy(sqlite3_vtab *pVtab){
+  sqlite3_free(pVtab);
+  return 0;
+}
+
+/*
+** Table constructor for the schema module.
+*/
+static int schemaPoolCreate(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  int rc = SQLITE_NOMEM;
+  schemapool_vtab *pVtab = sqlite3_malloc(sizeof(schemapool_vtab));
+  if( pVtab ){
+    memset(pVtab, 0, sizeof(schemapool_vtab));
+    rc = sqlite3_declare_vtab(db, SCHEMAPOOL_SCHEMA);
+    if( rc!=SQLITE_OK ){
+      sqlite3_free(pVtab);
+      pVtab = 0;
+    }
+  }
+  *ppVtab = (sqlite3_vtab *)pVtab;
+  return rc;
+}
+
+/*
+** Open a new cursor on the schema table.
+*/
+static int schemaPoolOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  int rc = SQLITE_NOMEM;
+  schemapool_cursor *pCur;
+  pCur = sqlite3_malloc(sizeof(schemapool_cursor));
+  if( pCur ){
+    memset(pCur, 0, sizeof(schemapool_cursor));
+    *ppCursor = (sqlite3_vtab_cursor*)pCur;
+    rc = SQLITE_OK;
+  }
+  return rc;
+}
+
+/*
+** Close a schema table cursor.
+*/
+static int schemaPoolClose(sqlite3_vtab_cursor *cur){
+  schemapool_cursor *pCur = (schemapool_cursor*)cur;
+  sqlite3_free(pCur->aData);
+  sqlite3_free(pCur);
+  return SQLITE_OK;
+}
+
+/*
+** Retrieve a column of data.
+*/
+static int schemaPoolColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
+  schemapool_cursor *pCur = (schemapool_cursor*)cur;
+  assert( i==0 || i==1 || i==2 || i==3 );
+  sqlite3_result_int64(ctx, pCur->aData[pCur->iRow*SCHEMAPOOL_NFIELD + i]);
+  return SQLITE_OK;
+}
+
+/*
+** Retrieve the current rowid.
+*/
+static int schemaPoolRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+  schemapool_cursor *pCur = (schemapool_cursor*)cur;
+  *pRowid = pCur->iRow + 1;
+  return SQLITE_OK;
+}
+
+static int schemaPoolEof(sqlite3_vtab_cursor *cur){
+  schemapool_cursor *pCur = (schemapool_cursor*)cur;
+  return pCur->iRow>=pCur->nRow;
+}
+
+/*
+** Advance the cursor to the next row.
+*/
+static int schemaPoolNext(sqlite3_vtab_cursor *cur){
+  schemapool_cursor *pCur = (schemapool_cursor*)cur;
+  pCur->iRow++;
+  return SQLITE_OK;
+}
+
+struct SchemaPool {
+  int nRef;                       /* Number of pointers to this object */
+  int nDelete;                    /* Schema objects deleted by ReleaseAll() */
+  u64 cksum;                      /* Checksum for this Schema contents */
+  Schema *pSchema;                /* Linked list of Schema objects */
+  Schema sSchema;                 /* The single dummy schema object */
+  SchemaPool *pNext;              /* Next element in schemaPoolList */
+};
+extern SchemaPool *sqlite3SchemaPoolList(void);
+
+/*
+** Reset a schemaPool table cursor.
+*/
+static int schemaPoolFilter(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  SchemaPool *pSPool;
+  schemapool_cursor *pCur = (schemapool_cursor*)pVtabCursor;
+
+  sqlite3_free(pCur->aData);
+  pCur->aData = 0;
+  pCur->nRow = 0;
+  pCur->iRow = 0;
+
+  for(pSPool = sqlite3SchemaPoolList(); pSPool; pSPool=pSPool->pNext){
+    pCur->nRow++;
+  }
+
+  if( pCur->nRow ){
+    int iRow = 0;
+    int nByte = SCHEMAPOOL_NFIELD * pCur->nRow * sizeof(i64);
+    pCur->aData = (i64*)sqlite3_malloc(nByte);
+    if( pCur->aData==0 ) return SQLITE_NOMEM;
+    for(pSPool = sqlite3SchemaPoolList(); pSPool; pSPool=pSPool->pNext){
+      Schema *p;
+      i64 nSchema = 0;
+      for(p=pSPool->pSchema; p; p=p->pNext){
+        nSchema++;
+      }
+      pCur->aData[0 + iRow*SCHEMAPOOL_NFIELD] = pSPool->cksum;
+      pCur->aData[1 + iRow*SCHEMAPOOL_NFIELD] = (i64)pSPool->nRef;
+      pCur->aData[2 + iRow*SCHEMAPOOL_NFIELD] = nSchema;
+      pCur->aData[3 + iRow*SCHEMAPOOL_NFIELD] = (i64)pSPool->nDelete;
+      iRow++;
+    }
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** Analyse the WHERE condition.
+*/
+static int schemaPoolBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  return SQLITE_OK;
+}
+
+/*
+** A virtual table module that merely echos method calls into TCL
+** variables.
+*/
+static sqlite3_module schemaPoolModule = {
+  0,                           /* iVersion */
+  schemaPoolCreate,
+  schemaPoolCreate,
+  schemaPoolBestIndex,
+  schemaPoolDestroy,
+  schemaPoolDestroy,
+  schemaPoolOpen,              /* xOpen - open a cursor */
+  schemaPoolClose,             /* xClose - close a cursor */
+  schemaPoolFilter,            /* xFilter - configure scan constraints */
+  schemaPoolNext,              /* xNext - advance a cursor */
+  schemaPoolEof,               /* xEof */
+  schemaPoolColumn,            /* xColumn - read data */
+  schemaPoolRowid,             /* xRowid - read data */
+  0,                           /* xUpdate */
+  0,                           /* xBegin */
+  0,                           /* xSync */
+  0,                           /* xCommit */
+  0,                           /* xRollback */
+  0,                           /* xFindMethod */
+  0,                           /* xRename */
+};
+
+/*
+** Decode a pointer to an sqlite3 object.
+*/
+extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);
+
+/*
+** Register the schema virtual table module.
+*/
+static int SQLITE_TCLAPI register_schemapool_module(
+  ClientData clientData, /* Not used */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3 *db;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  sqlite3_create_module(db, "schemapool", &schemaPoolModule, 0);
+#endif
+  return TCL_OK;
+}
+
+#endif /* ifdef SQLITE_ENABLE_SHARED_SCHEMA */
+#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_TEST) */
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int Sqlitetestschemapool_Init(Tcl_Interp *interp){
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  static struct {
+     char *zName;
+     Tcl_ObjCmdProc *xProc;
+     void *clientData;
+  } aObjCmd[] = {
+     { "register_schemapool_module", register_schemapool_module, 0 },
+  };
+  int i;
+  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
+    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 
+        aObjCmd[i].xProc, aObjCmd[i].clientData, 0);
+  }
+#endif /* ifdef SQLITE_ENABLE_SHARED_SCHEMA */
+  return TCL_OK;
+}
+

src/test_tclsh.c

@@ -76,6 +76,7 @@ const char *sqlite3TestInit(Tcl_Interp *interp){
   extern int Sqlitetest_malloc_Init(Tcl_Interp*);
   extern int Sqlitetest_mutex_Init(Tcl_Interp*);
   extern int Sqlitetestschema_Init(Tcl_Interp*);
+  extern int Sqlitetestschemapool_Init(Tcl_Interp*);
   extern int Sqlitetestsse_Init(Tcl_Interp*);
   extern int Sqlitetesttclvar_Init(Tcl_Interp*);
   extern int Sqlitetestfs_Init(Tcl_Interp*);
@@ -147,6 +148,7 @@ const char *sqlite3TestInit(Tcl_Interp *interp){
   Sqlitetest_malloc_Init(interp);
   Sqlitetest_mutex_Init(interp);
   Sqlitetestschema_Init(interp);
+  Sqlitetestschemapool_Init(interp);
   Sqlitetesttclvar_Init(interp);
   Sqlitetestfs_Init(interp);
   SqlitetestThread_Init(interp);

src/trigger.c

@@ -52,13 +52,34 @@ Trigger *sqlite3TriggerList(Parse *pParse, Table *pTab){
   Trigger *pList;           /* List of triggers to return */
   HashElem *p;              /* Loop variable for TEMP triggers */
 
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  char *zSchema = 0;
+  sqlite3 *db = pParse->db;
+  if( IsSharedSchema(db) ){
+    zSchema = db->aDb[sqlite3SchemaToIndex(db, pTab->pSchema)].zDbSName;
+  }
+#endif
+
   assert( pParse->disableTriggers==0 );
   pTmpSchema = pParse->db->aDb[1].pSchema;
   p = sqliteHashFirst(&pTmpSchema->trigHash);
   pList = pTab->pTrigger;
   while( p ){
     Trigger *pTrig = (Trigger *)sqliteHashData(p);
-    if( pTrig->pTabSchema==pTab->pSchema
+
+    int bSchemaMatch;
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+    if( zSchema ){
+      /* Shared-schema */
+      bSchemaMatch = (0==sqlite3StrICmp(pTrig->zTabSchema, zSchema));
+    }else
+#endif
+    {
+      /* Non-shared-schema */
+      bSchemaMatch = (pTrig->pTabSchema==pTab->pSchema);
+    }
+
+    if( bSchemaMatch
      && pTrig->table
      && 0==sqlite3StrICmp(pTrig->table, pTab->zName)
      && (pTrig->pTabSchema!=pTmpSchema || pTrig->bReturning)
@@ -68,7 +89,7 @@ Trigger *sqlite3TriggerList(Parse *pParse, Table *pTab){
     }else if( pTrig->op==TK_RETURNING ){
 #ifndef SQLITE_OMIT_VIRTUALTABLE
       assert( pParse->db->pVtabCtx==0 );
-#endif
+#endif 
       assert( pParse->bReturning );
       assert( &(pParse->u1.pReturning->retTrig) == pTrig );
       pTrig->table = pTab->zName;
@@ -202,6 +223,7 @@ void sqlite3BeginTrigger(
       }else{
         assert( !db->init.busy );
         sqlite3CodeVerifySchema(pParse, iDb);
+        VVA_ONLY( pParse->ifNotExists = 1; )
       }
       goto trigger_cleanup;
     }
@@ -258,6 +280,12 @@ void sqlite3BeginTrigger(
   pTrigger->zName = zName;
   zName = 0;
   pTrigger->table = sqlite3DbStrDup(db, pTableName->a[0].zName);
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  if( IsSharedSchema(db) && iDb==1 ){
+    int iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+    pTrigger->zTabSchema = sqlite3DbStrDup(db, db->aDb[iTabDb].zDbSName);
+  }
+#endif /* ifdef SQLITE_ENABLE_SHARED_SCHEMA */
   pTrigger->pSchema = db->aDb[iDb].pSchema;
   pTrigger->pTabSchema = pTab->pSchema;
   pTrigger->op = (u8)op;
@@ -381,7 +409,7 @@ void sqlite3FinishTrigger(
        pTrig->table, z);
     sqlite3DbFree(db, z);
     sqlite3ChangeCookie(pParse, iDb);
-    sqlite3VdbeAddParseSchemaOp(v, iDb,
+    sqlite3VdbeAddParseSchemaOp(pParse, iDb,
         sqlite3MPrintf(db, "type='trigger' AND name='%q'", zName), 0);
   }
 
@@ -600,6 +628,9 @@ void sqlite3DeleteTrigger(sqlite3 *db, Trigger *pTrigger){
   sqlite3DeleteTriggerStep(db, pTrigger->step_list);
   sqlite3DbFree(db, pTrigger->zName);
   sqlite3DbFree(db, pTrigger->table);
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  sqlite3DbFree(db, pTrigger->zTabSchema);
+#endif
   sqlite3ExprDelete(db, pTrigger->pWhen);
   sqlite3IdListDelete(db, pTrigger->pColumns);
   sqlite3DbFree(db, pTrigger);
@@ -671,6 +702,7 @@ void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger){
 
   iDb = sqlite3SchemaToIndex(pParse->db, pTrigger->pSchema);
   assert( iDb>=0 && iDb<db->nDb );
+  sqlite3SchemaWritable(pParse, iDb);
   pTable = tableOfTrigger(pTrigger);
   assert( (pTable && pTable->pSchema==pTrigger->pSchema) || iDb==1 );
 #ifndef SQLITE_OMIT_AUTHORIZATION
@@ -983,7 +1015,7 @@ static void codeReturningTrigger(
   }
   sqlite3ExprListDelete(db, sSelect.pEList);
   pNew = sqlite3ExpandReturning(pParse, pReturning->pReturnEL, pTab);
-  if( !db->mallocFailed ){
+  if( pParse->nErr==0 ){
     NameContext sNC;
     memset(&sNC, 0, sizeof(sNC));
     if( pReturning->nRetCol==0 ){
@@ -1163,7 +1195,9 @@ static TriggerPrg *codeRowTrigger(
   int iEndTrigger = 0;        /* Label to jump to if WHEN is false */
   Parse sSubParse;            /* Parse context for sub-vdbe */
 
-  assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) );
+  assert( pTrigger->zName==0 || IsSharedSchema(pParse->db)
+      || pTab==tableOfTrigger(pTrigger)
+  );
   assert( pTop->pVdbe );
 
   /* Allocate the TriggerPrg and SubProgram objects. To ensure that they
@@ -1270,7 +1304,9 @@ static TriggerPrg *getRowTrigger(
   Parse *pRoot = sqlite3ParseToplevel(pParse);
   TriggerPrg *pPrg;
 
-  assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) );
+  assert( pTrigger->zName==0 || IsSharedSchema(pParse->db)
+      || pTab==tableOfTrigger(pTrigger) 
+  );
 
   /* It may be that this trigger has already been coded (or is in the
   ** process of being coded). If this is the case, then an entry with

src/update.c

@@ -727,12 +727,22 @@ void sqlite3Update(
       /* Begin the database scan. 
       **
       ** Do not consider a single-pass strategy for a multi-row update if
-      ** there are any triggers or foreign keys to process, or rows may
-      ** be deleted as a result of REPLACE conflict handling. Any of these
-      ** things might disturb a cursor being used to scan through the table
-      ** or index, causing a single-pass approach to malfunction.  */
+      ** there is anything that might disrupt the cursor being used to do
+      ** the UPDATE:
+      **   (1) This is a nested UPDATE
+      **   (2) There are triggers
+      **   (3) There are FOREIGN KEY constraints
+      **   (4) There are REPLACE conflict handlers
+      **   (5) There are subqueries in the WHERE clause
+      */
       flags = WHERE_ONEPASS_DESIRED;
-      if( !pParse->nested && !pTrigger && !hasFK && !chngKey && !bReplace ){
+      if( !pParse->nested
+       && !pTrigger
+       && !hasFK
+       && !chngKey
+       && !bReplace
+       && (sNC.ncFlags & NC_Subquery)==0
+      ){
         flags |= WHERE_ONEPASS_MULTIROW;
       }
       pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere,0,0,0,flags,iIdxCur);

src/vacuum.c

@@ -125,6 +125,7 @@ void sqlite3Vacuum(Parse *pParse, Token *pNm, Expr *pInto){
   }
   if( iDb!=1 ){
     int iIntoReg = 0;
+    sqlite3SchemaWritable(pParse, iDb);
     if( pInto && sqlite3ResolveSelfReference(pParse,0,0,pInto,0)==0 ){
       iIntoReg = ++pParse->nMem;
       sqlite3ExprCode(pParse, pInto, iIntoReg);

src/vdbe.c

@@ -683,8 +683,7 @@ static u64 filterHash(const Mem *aMem, const Op *pOp){
     }else if( p->flags & MEM_Real ){
       h += sqlite3VdbeIntValue(p);
     }else if( p->flags & (MEM_Str|MEM_Blob) ){
-      h += p->n;
-      if( p->flags & MEM_Zero ) h += p->u.nZero;
+      /* no-op */
     }
   }
   return h;
@@ -3954,13 +3953,6 @@ case OP_Transaction: {
    && pOp->p5
    && (iMeta!=pOp->p3 || pDb->pSchema->iGeneration!=pOp->p4.i)
   ){
-    /*
-    ** IMPLEMENTATION-OF: R-03189-51135 As each SQL statement runs, the schema
-    ** version is checked to ensure that the schema has not changed since the
-    ** SQL statement was prepared.
-    */
-    sqlite3DbFree(db, p->zErrMsg);
-    p->zErrMsg = sqlite3DbStrDup(db, "database schema has changed");
     /* If the schema-cookie from the database file matches the cookie 
     ** stored with the in-memory representation of the schema, do
     ** not reload the schema from the database file.
@@ -3977,6 +3969,13 @@ case OP_Transaction: {
     if( db->aDb[pOp->p1].pSchema->schema_cookie!=iMeta ){
       sqlite3ResetOneSchema(db, pOp->p1);
     }
+    /*
+    ** IMPLEMENTATION-OF: R-03189-51135 As each SQL statement runs, the schema
+    ** version is checked to ensure that the schema has not changed since the
+    ** SQL statement was prepared.
+    */
+    sqlite3DbFree(db, p->zErrMsg);
+    p->zErrMsg = sqlite3DbStrDup(db, "database schema has changed");
     p->expired = 1;
     rc = SQLITE_SCHEMA;
 

src/vdbe.h

@@ -228,7 +228,7 @@ VdbeOp *sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp,int iLineno);
 #else
 # define sqlite3ExplainBreakpoint(A,B) /*no-op*/
 #endif
-void sqlite3VdbeAddParseSchemaOp(Vdbe*, int, char*, u16);
+void sqlite3VdbeAddParseSchemaOp(Parse*,int,char*,u16);
 void sqlite3VdbeChangeOpcode(Vdbe*, int addr, u8);
 void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1);
 void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2);

src/vdbeaux.c

@@ -486,8 +486,10 @@ void sqlite3VdbeExplainPop(Parse *pParse){
 ** The zWhere string must have been obtained from sqlite3_malloc().
 ** This routine will take ownership of the allocated memory.
 */
-void sqlite3VdbeAddParseSchemaOp(Vdbe *p, int iDb, char *zWhere, u16 p5){
+void sqlite3VdbeAddParseSchemaOp(Parse *pParse, int iDb, char *zWhere, u16 p5){
+  Vdbe *p = pParse->pVdbe;
   int j;
+  sqlite3SchemaWritable(pParse, iDb);
   sqlite3VdbeAddOp4(p, OP_ParseSchema, iDb, 0, 0, zWhere, P4_DYNAMIC);
   sqlite3VdbeChangeP5(p, p5);
   for(j=0; j<p->db->nDb; j++) sqlite3VdbeUsesBtree(p, j);

src/vdbeblob.c

@@ -135,6 +135,7 @@ int sqlite3_blob_open(
   Table *pTab;
   Incrblob *pBlob = 0;
   Parse sParse;
+  int bUnlock;            /* True to unlock reusable schemas before returning */
 
 #ifdef SQLITE_ENABLE_API_ARMOR
   if( ppBlob==0 ){
@@ -151,6 +152,7 @@ int sqlite3_blob_open(
 
   sqlite3_mutex_enter(db->mutex);
 
+  bUnlock = sqlite3LockReusableSchema(db);
   pBlob = (Incrblob *)sqlite3DbMallocZero(db, sizeof(Incrblob));
   while(1){
     sqlite3ParseObjectInit(&sParse,db);
@@ -336,6 +338,7 @@ int sqlite3_blob_open(
   }
 
 blob_open_out:
+  sqlite3UnlockReusableSchema(db, bUnlock);
   if( rc==SQLITE_OK && db->mallocFailed==0 ){
     *ppBlob = (sqlite3_blob *)pBlob;
   }else{

src/vtab.c

@@ -192,6 +192,24 @@ void sqlite3VtabLock(VTable *pVTab){
 VTable *sqlite3GetVTable(sqlite3 *db, Table *pTab){
   VTable *pVtab;
   assert( IsVirtual(pTab) );
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  if( IsSharedSchema(db) ){
+    int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+    if( iDb!=1 ){
+      VTable **pp;
+      for(pp=&db->aDb[iDb].pVTable; *pp; pp=&(*pp)->pNext){
+        if( sqlite3StrICmp(pTab->zName, (*pp)->zName)==0 ) break;
+      }
+      pVtab = *pp;
+      if( pVtab && pTab->nCol<=0 ){
+        *pp = pVtab->pNext;
+        sqlite3VtabUnlock(pVtab);
+        pVtab = 0;
+      }
+      return pVtab;
+    }
+  }
+#endif /* ifdef SQLITE_ENABLE_SHARED_SCHEMA */
   for(pVtab=pTab->u.vtab.p; pVtab && pVtab->db!=db; pVtab=pVtab->pNext);
   return pVtab;
 }
@@ -500,7 +518,7 @@ void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
 
     sqlite3VdbeAddOp0(v, OP_Expire);
     zWhere = sqlite3MPrintf(db, "name=%Q AND sql=%Q", pTab->zName, zStmt);
-    sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere, 0);
+    sqlite3VdbeAddParseSchemaOp(pParse, iDb, zWhere, 0);
     sqlite3DbFree(db, zStmt);
 
     iReg = ++pParse->nMem;
@@ -570,6 +588,7 @@ static int vtabCallConstructor(
   char *zModuleName;
   int iDb;
   VtabCtx *pCtx;
+  int nByte;                      /* Bytes of space to allocate */
 
   assert( IsVirtual(pTab) );
   azArg = (const char *const*)pTab->u.vtab.azArg;
@@ -589,7 +608,11 @@ static int vtabCallConstructor(
     return SQLITE_NOMEM_BKPT;
   }
 
-  pVTable = sqlite3MallocZero(sizeof(VTable));
+  nByte = sizeof(VTable);
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  nByte += sqlite3Strlen30(pTab->zName) + 1;
+#endif
+  pVTable = (VTable*)sqlite3MallocZero(nByte);
   if( !pVTable ){
     sqlite3OomFault(db);
     sqlite3DbFree(db, zModuleName);
@@ -597,6 +620,10 @@ static int vtabCallConstructor(
   }
   pVTable->db = db;
   pVTable->pMod = pMod;
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+  pVTable->zName = (char*)&pVTable[1];
+  memcpy(pVTable->zName, pTab->zName, nByte-sizeof(VTable));
+#endif
   pVTable->eVtabRisk = SQLITE_VTABRISK_Normal;
 
   iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
@@ -610,7 +637,9 @@ static int vtabCallConstructor(
   sCtx.pPrior = db->pVtabCtx;
   sCtx.bDeclared = 0;
   db->pVtabCtx = &sCtx;
+  pTab->nTabRef++;
   rc = xConstruct(db, pMod->pAux, nArg, azArg, &pVTable->pVtab, &zErr);
+  sqlite3DeleteTable(db, pTab);
   db->pVtabCtx = sCtx.pPrior;
   if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
   assert( sCtx.pTab==pTab );
@@ -639,12 +668,23 @@ static int vtabCallConstructor(
       int iCol;
       u16 oooHidden = 0;
       /* If everything went according to plan, link the new VTable structure
-      ** into the linked list headed by pTab->u.vtab.p. Then loop through the 
-      ** columns of the table to see if any of them contain the token "hidden".
-      ** If so, set the Column COLFLAG_HIDDEN flag and remove the token from
-      ** the type string.  */
-      pVTable->pNext = pTab->u.vtab.p;
-      pTab->u.vtab.p = pVTable;
+      ** into the linked list headed by pTab->u.vtab.p. Or, if this is a
+      ** reusable schema, into the linked list headed by Db.pVTable.
+      **
+      ** Then loop through the columns of the table to see if any of them
+      ** contain the token "hidden". If so, set the Column COLFLAG_HIDDEN flag
+      ** and remove the token from the type string.  */
+#ifdef SQLITE_ENABLE_SHARED_SCHEMA
+      if( IsSharedSchema(db) && iDb!=1 ){
+        pVTable->pNext = db->aDb[iDb].pVTable;
+        db->aDb[iDb].pVTable = pVTable;
+      }else
+#endif /* ifdef SQLITE_ENABLE_SHARED_SCHEMA */
+      {
+        assert( IsVirtual(pTab) );
+        pVTable->pNext = pTab->u.vtab.p;
+        pTab->u.vtab.p = pVTable;
+      }
 
       for(iCol=0; iCol<pTab->nCol; iCol++){
         char *zType = sqlite3ColumnType(&pTab->aCol[iCol], "");
@@ -699,6 +739,7 @@ int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){
   assert( pTab );
   assert( IsVirtual(pTab) );
   if( sqlite3GetVTable(db, pTab) ){
+    assert( !IsVirtual(pTab) || pTab->nCol>0 );
     return SQLITE_OK;
   }
 

src/where.c

@@ -1123,6 +1123,10 @@ static SQLITE_NOINLINE void sqlite3ConstructBloomFilter(
   Vdbe *v = pParse->pVdbe;             /* VDBE under construction */
   WhereLoop *pLoop = pLevel->pWLoop;   /* The loop being coded */
   int iCur;                            /* Cursor for table getting the filter */
+  IndexedExpr *saved_pIdxEpr;          /* saved copy of Parse.pIdxEpr */
+
+  saved_pIdxEpr = pParse->pIdxEpr;
+  pParse->pIdxEpr = 0;
 
   assert( pLoop!=0 );
   assert( v!=0 );
@@ -1179,9 +1183,8 @@ static SQLITE_NOINLINE void sqlite3ConstructBloomFilter(
       int r1 = sqlite3GetTempRange(pParse, n);
       int jj;
       for(jj=0; jj<n; jj++){
-        int iCol = pIdx->aiColumn[jj];
         assert( pIdx->pTable==pItem->pTab );
-        sqlite3ExprCodeGetColumnOfTable(v, pIdx->pTable, iCur, iCol,r1+jj);
+        sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iCur, jj, r1+jj);
       }
       sqlite3VdbeAddOp4Int(v, OP_FilterAdd, pLevel->regFilter, 0, r1, n);
       sqlite3ReleaseTempRange(pParse, r1, n);
@@ -1212,6 +1215,7 @@ static SQLITE_NOINLINE void sqlite3ConstructBloomFilter(
     }
   }while( iLevel < pWInfo->nLevel );
   sqlite3VdbeJumpHere(v, addrOnce);
+  pParse->pIdxEpr = saved_pIdxEpr;
 }
 
 
@@ -1510,6 +1514,7 @@ static int whereKeyStats(
   assert( pRec!=0 );
   assert( pIdx->nSample>0 );
   assert( pRec->nField>0 );
+ 
 
   /* Do a binary search to find the first sample greater than or equal
   ** to pRec. If pRec contains a single field, the set of samples to search
@@ -1555,7 +1560,12 @@ static int whereKeyStats(
   ** it is extended to two fields. The duplicates that this creates do not 
   ** cause any problems.
   */
-  nField = MIN(pRec->nField, pIdx->nSample);
+  if( !HasRowid(pIdx->pTable) && IsPrimaryKeyIndex(pIdx) ){
+    nField = pIdx->nKeyCol;
+  }else{
+    nField = pIdx->nColumn;
+  }
+  nField = MIN(pRec->nField, nField);
   iCol = 0;
   iSample = pIdx->nSample * nField;
   do{
@@ -5283,6 +5293,10 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
       if( pFrom->isOrdered==pWInfo->pOrderBy->nExpr ){
         pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
       }
+      if( pWInfo->pSelect->pOrderBy
+       && pWInfo->nOBSat > pWInfo->pSelect->pOrderBy->nExpr ){
+        pWInfo->nOBSat = pWInfo->pSelect->pOrderBy->nExpr;
+      }
     }else{
       pWInfo->revMask = pFrom->revLoop;
       if( pWInfo->nOBSat<=0 ){
@@ -5694,6 +5708,9 @@ static SQLITE_NOINLINE void whereAddIndexedExpr(
     p->iIdxCur = iIdxCur;
     p->iIdxCol = i;
     p->bMaybeNullRow = bMaybeNullRow;
+    if( sqlite3IndexAffinityStr(pParse->db, pIdx) ){
+      p->aff = pIdx->zColAff[i];
+    }
 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
     p->zIdxName = pIdx->zName;
 #endif

src/whereexpr.c

@@ -1856,7 +1856,7 @@ void sqlite3WhereTabFuncArgs(
     pRhs = sqlite3PExpr(pParse, TK_UPLUS, 
         sqlite3ExprDup(pParse->db, pArgs->a[j].pExpr, 0), 0);
     pTerm = sqlite3PExpr(pParse, TK_EQ, pColRef, pRhs);
-    if( pItem->fg.jointype & (JT_LEFT|JT_LTORJ) ){
+    if( pItem->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT) ){
       joinType = EP_OuterON;
     }else{
       joinType = EP_InnerON;

test/bloom1.test

@@ -99,6 +99,78 @@ do_eqp_test 2.1 {
   |     |--SCAN transit
   |     `--SEARCH objs USING COVERING INDEX objs_cspo (o=? AND p=?)
   `--SCAN transit
-} 
+}
 
+# 2023-02-28
+# https://sqlite.org/forum/forumpost/0846211821
+#
+# Bloom filter gives an incorrect result if the collating sequence is
+# anything other than binary.
+#
+reset_db
+do_execsql_test 3.1 {
+  CREATE TABLE t0(x TEXT COLLATE rtrim);
+  INSERT INTO t0(x) VALUES ('a'), ('b'), ('c');
+  CREATE VIEW v0(y) AS SELECT DISTINCT x FROM t0;
+  SELECT count(*) FROM t0, v0 WHERE x='b ';
+} 3
+do_eqp_test 3.2 {
+  SELECT count(*) FROM t0, v0 WHERE x='b ';
+} {
+  QUERY PLAN
+  |--CO-ROUTINE v0
+  |  |--SCAN t0
+  |  `--USE TEMP B-TREE FOR DISTINCT
+  |--SCAN v0
+  `--SEARCH t0 USING AUTOMATIC PARTIAL COVERING INDEX (x=?)
+}
+# ^^^^^--- The key feature in the previous result is that no Bloom filter
+# is used.  In the following, a Bloom filter is used because the data type
+# is INT instead of TEXT.
+do_execsql_test 3.3 {
+  CREATE TABLE t1(x INT COLLATE rtrim);
+  INSERT INTO t1(x) VALUES ('a'), ('b'), ('c');
+  CREATE VIEW v1(y) AS SELECT DISTINCT x FROM t1;
+  SELECT count(*) FROM t1, v1 WHERE x='b ';
+} 3
+
+# 2023-03-14 
+# https://sqlite.org/forum/forumpost/d47a0e8e3a
+# https://sqlite.org/forum/forumpost/2e427099d5
+#
+# Both reports are for the same problem - using a Bloom filter on an
+# expression index can cause issues.
+#
+reset_db
+do_execsql_test 4.1 {
+  CREATE TABLE t1(x TEXT, y INT, z TEXT);
+  INSERT INTO t1(rowid,x,y,z) VALUES(12,'aa','bb','aa');
+  CREATE INDEX i1x ON t1(1 IS true,z);
+  CREATE TABLE t0(x TEXT);
+  INSERT INTO t0(rowid,x) VALUES(4,'aa');
+  ANALYZE sqlite_schema;
+  INSERT INTO sqlite_stat1 VALUES('t0',NULL,'20');
+  INSERT INTO sqlite_stat1 VALUES('t1','i1x','18 18 2');
+  ANALYZE sqlite_schema;
+}
+do_execsql_test 4.2 {
+  SELECT * FROM t0 NATURAL JOIN t1 WHERE z=t1.x;
+} {aa bb aa}
+do_execsql_test 4.3 {
+  DROP TABLE t0;
+  CREATE TABLE t0(a TEXT);
+  INSERT INTO t0 VALUES ('xyz');
+  CREATE INDEX t0x ON t0(a IS FALSE) WHERE false;
+  DROP TABLE t1;
+  CREATE TABLE t1(b INT);
+  INSERT INTO t1 VALUES('aaa'),('bbb'),('ccc'),('ddd'),(NULL);
+  CREATE TABLE t2(c REAL);
+  INSERT INTO t2 VALUES(7);
+  ANALYZE;
+  CREATE INDEX t2x ON t2(true IN ());
+}
+do_execsql_test 4.4 {
+  SELECT * FROM t0 LEFT JOIN t1 LEFT JOIN t2 ON (b NOTNULL)==(c IN ()) WHERE c;
+} {xyz {} 7.0}
+ 
 finish_test

test/corruptL.test

@@ -1269,11 +1269,14 @@ do_test 15.0 {
 }]} {}
 
 extra_schema_checks 0
-do_execsql_test 15.1 {
+do_catchsql_test 15.1 {
   PRAGMA cell_size_check = 0;
   UPDATE c1 SET c= NOT EXISTS(SELECT 1 FROM c1 ORDER BY (SELECT 1 FROM c1 ORDER BY a)) +10 WHERE d BETWEEN 4 AND 7;
-} {}
+} {1 {database disk image is malformed}}
 extra_schema_checks 1
+do_execsql_test 15.2 {
+  PRAGMA integrity_check;
+} {/in database main/}
 
 #-------------------------------------------------------------------------
 reset_db

test/countofview.test

@@ -51,6 +51,29 @@ do_execsql_test 2.1 {
   SELECT count(*) FROM v1 GROUP BY y;
 } {3 3}
 
+# 2023-03-01 dbsqlfuzz ef8623915d843b150c159166ee4548c78cc6895a
+# count-of-view should not apply to CTEs.
+#
+ifcapable progress {
+  proc progress_stop args {return 1}
+  db progress 1000 progress_stop
+  do_catchsql_test 3.1 {
+    WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c)
+    SELECT count(*) FROM c;
+  } {1 interrupted}
+}
 
+# 2023-03-07 dbsqlfuzz 23d782160b71c3f8f535ccb2da313dfc8eb8c631
+#
+do_execsql_test 4.1 {
+  DROP TABLE t1;
+  DROP TABLE t2;
+  DROP TABLE t3;
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b TEXT);
+  INSERT INTO t1 VALUES(4,'four');
+  CREATE TABLE t2(c INTEGER PRIMARY KEY, d TEXT);
+  CREATE VIEW t3 AS SELECT a, b FROM t1 UNION ALL SELECT c, d FROM t2;
+  SELECT count(*) FROM t3 ORDER BY sum(a);
+} 1
 
 finish_test

test/delete.test

@@ -416,4 +416,28 @@ do_execsql_test delete-11.1 {
 } {6 2 12 4 18 6 19 23 20 40}
 
 
+# 2023-03-15
+# https://sqlite.org/forum/forumpost/e61252062c9d286d
+#
+# When the WHERE clause of a DELETE statement contains a subquery
+# which uses the table that is being deleted from and there is a
+# short-circuit operator of some kind in the WHERE clause such that
+# the subquery might not run right away, then the subquery might
+# run after one or more rows have been deleted, which can change
+# the result of the subquery, and result in the wrong answer.
+#
+# Similar problem for UPDATE tested by update-21.4
+# https://sqlite.org/forum/forumpost/0007d1fdb1
+#
+reset_db
+do_execsql_test delete-12.0 {
+  CREATE TABLE t0(vkey INTEGER, pkey INTEGER,c1 INTEGER);
+  INSERT INTO t0 VALUES(2,1,-20),(2,2,NULL),(2,3,0),(8,4,95);
+  DELETE FROM t0 WHERE NOT (
+    (t0.vkey <= t0.c1) AND
+    (t0.vkey <> (SELECT vkey FROM t0 ORDER BY vkey LIMIT 1 OFFSET 2))
+  );
+  SELECT * FROM t0;
+} {8 4 95}
+
 finish_test

test/distinct.test

@@ -348,5 +348,61 @@ foreach {tn idx} {
   }
 }
 
+# 2023-03-16
+# https://sqlite.org/forum/forumpost/16ce2bb7a639e29b
+# ticket c36cdb4afd504dc1
+# ticket 4051a7f931d9ba24
+# ticket d6fd512f50513ab7
+#
+do_execsql_test 10.1 {
+  SELECT  DISTINCT
+    1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+    1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+    1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+    1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+    1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+    1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+    1,  1,  1,  1,  1
+  ORDER  BY
+   'x','x','x','x','x','x','x','x','x','x',
+   'x','x','x','x','x','x','x','x','x','x',
+   'x','x','x','x','x','x','x','x','x','x',
+   'x','x','x','x','x','x','x','x','x','x',
+   'x','x','x','x','x','x','x','x','x','x',
+   'x','x','x','x','x','x','x','x','x','x',
+   'x','x','x','x';
+} {1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1}
+do_execsql_test 10.2 {
+  EXPLAIN
+  SELECT  DISTINCT
+    1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+    1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+    1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+    1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+    1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+    1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
+    1,  1,  1,  1,  1
+  ORDER  BY
+   'x','x','x','x','x','x','x','x','x','x',
+   'x','x','x','x','x','x','x','x','x','x',
+   'x','x','x','x','x','x','x','x','x','x',
+   'x','x','x','x','x','x','x','x','x','x',
+   'x','x','x','x','x','x','x','x','x','x',
+   'x','x','x','x','x','x','x','x','x','x',
+   'x','x','x','x';
+} {/0 Init 0 /}
+do_execsql_test 10.3 {
+  EXPLAIN  CREATE  TABLE t2 AS  SELECT  DISTINCT ':memory:', 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7 ORDER  BY '%J%j%w%s', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', '%J%j%w%s', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 42e-300, 'unixepoch', 'unixepoch', 'unixepoch' LIMIT 0xda;
+} {/0 Init 0/}
+do_execsql_test 10.4 {
+  DROP TABLE IF EXISTS t0;
+  CREATE  TABLE t0 AS  SELECT  DISTINCT 0xda, 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 0xda-0xda-42e-300, 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0', 'lit0' ORDER  BY '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%Y-%m-%d', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', 'lit0', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', 'auto', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', ':memory:', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '%%', '';
+  SELECT count(*) FROM t0;
+} {1}
+do_execsql_test 10.5 {
+  DROP TABLE IF EXISTS t2;
+  CREATE  TABLE t2 AS  SELECT  DISTINCT ':memory:', 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 0.0*7/0, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7 ORDER  BY '%J%j%w%s', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', '%J%j%w%s', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 'unixepoch', 42e-300, 'unixepoch', 'unixepoch', 'unixepoch' LIMIT 0xda;
+  SELECT count(*) FROM t2;
+} {1}
 
 finish_test

test/distinct2.test

@@ -301,4 +301,16 @@ do_execsql_test 3030 {
   {} 1 a
 }
 
+#-------------------------------------------------------------------------
+#
+reset_db
+
+do_execsql_test 4010 {
+  CREATE TABLE t1(a, b COLLATE RTRIM);
+  INSERT INTO t1 VALUES(1, ''), (2, ' '), (3, '  ');
+}
+do_execsql_test 4020 {
+  SELECT b FROM t1 UNION SELECT 1;
+} {1 {  }}
+
 finish_test

test/gencol1.test

@@ -615,4 +615,58 @@ do_execsql_test gencol1-22.1 {
      AND (y.a=2 OR (x.b LIKE '2*' AND y.a=x.b));
 } {2 2 2 2}
 
+
+# 2023-03-02 dbsqlfuzz 65f5eb57f8859344d5f1f33e08c77ee12960ed83
+#
+set typelist {ANY INT REAL BLOB TEXT {}}
+set cnt 0
+foreach t1 $typelist {
+  foreach t2 $typelist {
+    incr cnt
+    db eval "
+      DROP TABLE IF EXISTS t1;
+      CREATE TABLE t1(
+        x $t1,
+        a $t2 AS (x) VIRTUAL,
+        b BLOB AS (x) VIRTUAL
+      );
+      CREATE INDEX x2 ON t1(a);
+      INSERT INTO t1(x) VALUES(NULL),('1'),(2),(3.5),('xyz');
+    "
+    set x1 [lsort [db eval {SELECT typeof(b) FROM t1}]]
+    do_test gencol1-23.1.$cnt {
+      lsort [db eval {SELECT typeof(b) FROM t1 INDEXED BY x2}]
+    } $x1
+  }
+}
+do_execsql_test gencol1-23.2 {
+  DROP TABLE t1;
+  CREATE TABLE t1(
+    x,
+    a INT AS (x) VIRTUAL,
+    b BLOB AS (x) VIRTUAL
+  );
+  CREATE INDEX x2 ON t1(a);
+  INSERT INTO t1(x) VALUES(NULL),('1'),('xyz'),(2),(3.5);
+  SELECT quote(a) FROM t1 INDEXED BY x2;
+} {NULL 1 2 3.5 'xyz'}
+do_execsql_test gencol1-23.3 {
+  EXPLAIN SELECT a FROM t1 INDEXED BY x2;
+} {~/Column 0/}
+#    ^^^^^^^^---- verfies that x2 acts like a covering index
+do_execsql_test gencol1-23.4 {
+  EXPLAIN SELECT b FROM t1 INDEXED BY x2;
+} {/Column 0/}
+#  ^^^^^^^^^^--- Must reference the original table in this case because
+# of the different datatype on column b.
+
+# 2023-03-07 https://sqlite.org/forum/forumpost/b312e075b5
+#
+do_execsql_test gencol1-23.5 {
+  CREATE TABLE v0(c1 INT, c2 AS (RAISE(IGNORE)));
+}
+do_catchsql_test gencol1-23.6 {
+  SELECT * FROM v0;
+} {1 {RAISE() may only be used within a trigger-program}}
+
 finish_test

test/join2.test

@@ -354,5 +354,78 @@ do_execsql_test 9.11 {
   SELECT ccc, ccc IS NULL AS ddd FROM t1 LEFT JOIN v2;
 } {{} 1}
 
+# 2023-03-01 https://sqlite.org/forum/forumpost/26387ea7ef
+# When flattening a VIEW which is the RHS of a LEFT JOIN, always put
+# an TK_IF_NULL_ROW operator on all accesses, even TK_COLUMN nodes, since
+# the TK_COLUMN might reference an outer subquery.
+#
+reset_db
+db null NULL
+do_execsql_test 10.1 {
+  CREATE TABLE t1 (x INTEGER);
+  INSERT INTO t1 VALUES(1);   -- Some true value
+  CREATE TABLE t2 (z TEXT);
+  INSERT INTO t2 VALUES('some value');
+  CREATE TABLE t3(w TEXT);
+  INSERT INTO t3 VALUES('some other value');
+}
+do_execsql_test 10.2 {
+  SELECT (
+    SELECT 1 FROM t2 LEFT JOIN (SELECT x AS v FROM t3) ON 500=v WHERE (v OR FALSE)
+  ) FROM t1;
+} NULL
+do_execsql_test 10.3 {
+  SELECT (
+    SELECT 1 FROM t2 LEFT JOIN (SELECT x AS v FROM t3) ON 500=v WHERE (v)
+  ) FROM t1;
+} NULL
+optimization_control db all 0
+do_execsql_test 10.4 {
+  SELECT (
+    SELECT 1 FROM t2 LEFT JOIN (SELECT x AS v FROM t3) ON 500=v WHERE (v OR FALSE)
+  ) FROM t1;
+} NULL
+
+# 2023-03-02 https://sqlite.org/forum/forumpost/402f05296d
+#
+# The TK_IF_NULL_ROW expression node must ensure that it does not overwrite
+# the result register of an OP_Once subroutine.
+#
+optimization_control db all 1
+do_execsql_test 11.1 {
+  DROP TABLE t1;
+  DROP TABLE t2;
+  DROP TABLE t3;
+  CREATE TABLE t1(x TEXT, y INTEGER);
+  INSERT INTO t1(x,y) VALUES(NULL,-2),(NULL,1),('0',2);
+  CREATE TABLE t2(z INTEGER);
+  INSERT INTO t2(z) VALUES(2),(-2);
+  CREATE VIEW t3 AS SELECT z, (SELECT count(*) FROM t1) AS w FROM t2;
+  SELECT * FROM t1 LEFT JOIN t3 ON y=z;
+} {NULL -2 -2 3 NULL 1 NULL NULL 0 2 2 3}
+
+# 2023-03-11 https://sqlite.org/forum/forumpost/b405033490fa56d9
+# The fix that test 11.1 above checks also caused a performance regression.
+# This test case verifies that the performance regression has been resolved.
+#
+do_execsql_test 12.1 {
+  DROP TABLE t1;
+  DROP TABLE t2;
+  DROP VIEW t3;
+  CREATE TABLE t1(a INTEGER PRIMARY KEY);
+  WITH RECURSIVE c(n) AS (VALUES(1) UNION ALL SELECT n+1 FROM c WHERE n<100)
+    INSERT INTO t1(a) SELECT n FROM c;
+  CREATE VIEW t2(b) AS SELECT a FROM t1;
+}
+do_vmstep_test 12.2 {
+  SELECT * FROM t1 LEFT JOIN t2 ON a=b LIMIT 10 OFFSET 98;
+} 2000 {99 99 100 100}
+do_eqp_test 12.3 {
+  SELECT * FROM t1 LEFT JOIN t2 ON a=b LIMIT 10 OFFSET 98;
+} {
+  QUERY PLAN
+  |--SCAN t1
+  `--SEARCH t1 USING INTEGER PRIMARY KEY (rowid=?) LEFT-JOIN
+}
 
 finish_test

test/notnull2.test

@@ -28,24 +28,6 @@ do_execsql_test 1.0 {
   INSERT INTO t2 SELECT * FROM t1;
 }
 
-proc do_vmstep_test {tn sql nstep {res {}}} {
-  uplevel [list do_execsql_test $tn.0 $sql $res]
-
-  set vmstep [db status vmstep]
-  if {[string range $nstep 0 0]=="+"} {
-    set body "if {$vmstep<$nstep} {
-      error \"got $vmstep, expected more than [string range $nstep 1 end]\"
-    }"
-  } else {
-    set body "if {$vmstep>$nstep} {
-      error \"got $vmstep, expected less than $nstep\"
-    }"
-  }
-
-  # set name "$tn.vmstep=$vmstep,expect=$nstep"
-  set name "$tn.1"
-  uplevel [list do_test $name $body {}]
-}
 
 do_vmstep_test 1.1.1 {
   SELECT * FROM t1 LEFT JOIN t2 WHERE a=c AND d IS NULL;

test/returning1.test

@@ -212,13 +212,13 @@ do_execsql_test 10.2 {
   END;
 }
 
-do_catchsql_test 10.3 {
+do_catchsql_test 10.3a {
   INSERT INTO t1(a, b) VALUES(1234, 5678) RETURNING rowid;
-} {1 {no such column: rowid}}
+} {1 {no such column: new.rowid}}
 
-do_catchsql_test 10.3 {
+do_catchsql_test 10.3b {
   UPDATE t1 SET a='z' WHERE b='y' RETURNING rowid;
-} {1 {no such column: rowid}}
+} {1 {no such column: new.rowid}}
 
 do_execsql_test 10.4 {
   SELECT * FROM log;
@@ -408,4 +408,34 @@ do_execsql_test 17.0 {
   UPDATE bug SET x=NULL WHERE id = 20 RETURNING quote(x), x IS NULL;
 } {NULL 1}
 
+# 2023-03-08 https://sqlite.org/forum/forumpost/f5a2b1db87
+# NULL pointer dereference following an error.
+#
+do_execsql_test 18.0 {
+  CREATE TABLE v0(c1 INT);
+  CREATE VIEW view_2(c1) AS SELECT CASE WHEN c1 COLLATE TRUE THEN TRUE ELSE TRUE END FROM v0;
+}
+do_catchsql_test 18.1 {
+  INSERT INTO view_2 DEFAULT VALUES RETURNING *;
+} {1 {no such collation sequence: TRUE}}
+
+# 2023-03-16 
+# https://sqlite.org/forum/forumpost/c99d6e0329
+# ticket d15b3a4ea901ef0d
+# ticket 89d259d45b855a0d
+#
+# A RETURNING clause on an IF NOT EXISTS trigger does not generate
+# an error if the trigger already exists.
+#
+do_execsql_test 19.0 {
+  DROP TABLE IF EXISTS t1;CREATE TABLE t1(a);
+  CREATE TRIGGER r1 AFTER UPDATE ON t1 BEGIN VALUES(0); END;
+} {}
+do_catchsql_test 19.1 {
+  CREATE TRIGGER IF NOT EXISTS r1 AFTER DELETE ON t1 BEGIN
+    INSERT  INTO t1(a) VALUES (1) RETURNING FALSE;
+    INSERT  INTO t1(a) VALUES (2) RETURNING TRUE;
+  END;
+} {0 {}}
+
 finish_test

test/reuse1.test

@@ -0,0 +1,394 @@
+# 2017 August 9
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+#
+
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix reuse1
+
+ifcapable !sharedschema {
+  finish_test
+  return
+}
+
+forcedelete test.db2
+sqlite3 db2 test.db2
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(x INTEGER PRIMARY KEY, y UNIQUE, z);
+  CREATE INDEX i1 ON t1(z);
+  PRAGMA schema_version;
+} {2}
+
+do_execsql_test -db db2 1.1 {
+  CREATE TABLE t1(x INTEGER PRIMARY KEY, y UNIQUE, z);
+  CREATE INDEX i1 ON t1(z);
+  PRAGMA schema_version;
+} {2}
+
+do_test 1.2 {
+  db close
+  db2 close
+  sqlite3 db2 test.db2 -shared-schema 1
+  sqlite3 db  test.db -shared-schema 1
+} {}
+
+do_execsql_test -db db2 1.3.1 {
+  INSERT INTO t1 VALUES(1, 2, 3);
+  INSERT INTO t1 VALUES(4, 5, 6);
+}
+
+do_execsql_test 1.3.2 {
+  SELECT * FROM t1;
+  PRAGMA integrity_check;
+} {ok}
+
+do_execsql_test -db db2 1.3.3 {
+  SELECT * FROM t1;
+  PRAGMA integrity_check;
+} {1 2 3 4 5 6 ok}
+
+sqlite3 db3 test.db2
+do_execsql_test -db db3 1.4.1 {
+  ALTER TABLE t1 ADD COLUMN a;
+}
+do_execsql_test -db db2 1.4.2 {
+  SELECT * FROM t1;
+} {1 2 3 {} 4 5 6 {}}
+do_execsql_test 1.4.3 {
+  SELECT * FROM t1;
+} {}
+
+db3 close
+sqlite3 db3 test.db
+do_execsql_test -db db3 1.5.0 {
+  CREATE TRIGGER tr1 AFTER INSERT ON t1 BEGIN
+    SELECT 1, 2, 3;
+  END;
+}
+
+# Check that the schema cannot be modified if the db was opened with
+# SQLITE_OPEN_REUSE_SCHEMA.
+#
+foreach {tn sql} {
+  1  { CREATE TABLE t2(x, y) }
+  2  { CREATE INDEX i2 ON t1(z) }
+  3  { CREATE VIEW v2 AS SELECT * FROM t2 }
+  4  { ALTER TABLE t1 RENAME TO t3 }
+  5  { ALTER TABLE t1 ADD COLUMN xyz }
+  6  { VACUUM }
+  7  { DROP INDEX i1 }
+  8  { DROP TABLE t1 }
+  9  { DROP TRIGGER tr1 }
+  10 { ANALYZE }
+  11 { ALTER TABLE t1 RENAME z TO zzz }
+} {
+  do_catchsql_test 1.5.$tn $sql {1 {attempt to modify read-only schema}}
+}
+
+#-------------------------------------------------------------------------
+#
+reset_db
+forcedelete test.db2
+ifcapable fts5 {
+  do_execsql_test 2.0 {
+    CREATE VIRTUAL TABLE ft USING fts5(a);
+    INSERT INTO ft VALUES('one'), ('two'), ('three');
+    ATTACH 'test.db2' AS aux;
+    CREATE VIRTUAL TABLE aux.ft USING fts5(a);
+    INSERT INTO aux.ft VALUES('aux1'), ('aux2'), ('aux3');
+  }
+
+  db close
+  sqlite3 db  test.db -shared-schema 1
+
+  do_execsql_test 2.1 {
+    ATTACH 'test.db2' AS aux;
+    SELECT * FROM main.ft;
+  } {one two three}
+
+breakpoint
+  do_execsql_test 2.2 {
+    SELECT * FROM aux.ft;
+  } {aux1 aux2 aux3}
+
+  do_execsql_test 2.2 {
+    SELECT * FROM aux.ft_content;
+  } {1 aux1 2 aux2 3 aux3}
+}
+
+#-------------------------------------------------------------------------
+#
+reset_db
+forcedelete test.db2
+do_execsql_test 3.0 {
+  CREATE TABLE t1(a PRIMARY KEY, b, c);
+  CREATE VIEW v1 AS SELECT * FROM t1;
+  CREATE TRIGGER v1_ins INSTEAD OF INSERT ON v1 BEGIN
+    INSERT INTO t1 VALUES(new.a, new.b, new.c);
+  END;
+  CREATE TRIGGER v1_del INSTEAD OF DELETE ON v1 BEGIN
+    DELETE FROM t1 WHERE a=old.a;
+  END;
+  CREATE TRIGGER v1_up INSTEAD OF UPDATE ON v1 BEGIN
+    UPDATE t1 SET a=new.a, b=new.b, c=new.c WHERE a=old.a;
+  END;
+}
+forcecopy test.db test.db2
+
+do_test 3.1 {
+  sqlite3 db2 test.db2
+  execsql { INSERT INTO t1 VALUES(1, 2, 3) } db
+  execsql { INSERT INTO t1 VALUES(4, 5, 6) } db2
+  db2 close
+  execsql { ATTACH 'test.db2' AS aux; }
+} {}
+
+do_execsql_test 3.2 {
+  SELECT * FROM main.v1;
+} {1 2 3}
+
+do_execsql_test 3.3 {
+  SELECT * FROM aux.v1;
+} {4 5 6}
+
+db close
+sqlite3 db test.db -shared-schema 1
+
+do_execsql_test 3.4 { ATTACH 'test.db2' AS aux } {}
+do_execsql_test 3.5 { SELECT * FROM main.v1 } {1 2 3}
+do_execsql_test 3.6 { SELECT * FROM aux.v1  } {4 5 6}
+
+do_execsql_test 3.7.1 { INSERT INTO aux.t1 VALUES(8, 9, 10); }
+do_execsql_test 3.7.2 { SELECT * FROM main.v1 } {1 2 3}
+do_execsql_test 3.7.3 { SELECT * FROM aux.v1  } {4 5 6 8 9 10}
+
+do_execsql_test 3.8.1 { DELETE FROM aux.t1 WHERE b=5 }
+do_execsql_test 3.8.2 { SELECT * FROM main.v1 } {1 2 3}
+do_execsql_test 3.8.3 { SELECT * FROM aux.v1  } {8 9 10}
+
+do_execsql_test 3.9.1 { UPDATE aux.t1 SET b='abc' }
+do_execsql_test 3.9.2 { SELECT * FROM main.v1 } {1 2 3}
+do_execsql_test 3.9.3 { SELECT * FROM aux.v1  } {8 abc 10}
+
+do_execsql_test 3.10.1 { INSERT INTO aux.v1 VALUES(11, 12, 13) }
+do_execsql_test 3.10.2 { SELECT * FROM main.v1 } {1 2 3}
+do_execsql_test 3.10.3 { SELECT * FROM aux.v1  } {8 abc 10 11 12 13}
+
+do_execsql_test 3.11.1 { DELETE FROM aux.v1 WHERE b='abc' }
+do_execsql_test 3.11.2 { SELECT * FROM main.v1 } {1 2 3}
+do_execsql_test 3.11.3 { SELECT * FROM aux.v1  } {11 12 13}
+
+do_execsql_test 3.12.1 { UPDATE aux.v1 SET b='def' }
+do_execsql_test 3.12.2 { SELECT * FROM main.v1 } {1 2 3}
+do_execsql_test 3.12.3 { SELECT * FROM aux.v1  } {11 def 13}
+
+do_execsql_test 3.13.1 {
+  CREATE TEMP TRIGGER xyz AFTER INSERT ON aux.t1 BEGIN
+    INSERT INTO v1 VALUES(new.a, new.b, new.c);
+  END
+}
+do_execsql_test 3.13.2 {
+  INSERT INTO aux.v1 VALUES('x', 'y', 'z');
+}
+do_execsql_test 3.13.3 {
+  SELECT * FROM v1;
+} {1 2 3 x y z}
+
+#-------------------------------------------------------------------------
+#
+reset_db
+forcedelete test.db2
+do_execsql_test 4.0 {
+  CREATE TABLE t1(a PRIMARY KEY, b, c UNIQUE);
+  CREATE TABLE del(a, b, c);
+  CREATE TRIGGER tr1 AFTER DELETE ON t1 BEGIN
+    INSERT INTO del VALUES(old.a, old.b, old.c);
+  END;
+}
+forcecopy test.db test.db2
+
+db close
+sqlite3 db test.db -shared-schema 1
+execsql { 
+  ATTACH 'test.db2' AS aux;
+  PRAGMA recursive_triggers = 1;
+}
+
+do_execsql_test 4.1 {
+  INSERT INTO main.t1 VALUES(1, 2, 3);
+  INSERT INTO aux.t1 VALUES(4, 5, 6);
+}
+
+do_execsql_test 4.2.1 {
+  INSERT OR REPLACE INTO aux.t1 VALUES('a', 'b', 6);
+  SELECT * FROM aux.t1;
+} {a b 6}
+do_execsql_test 4.2.2 { SELECT * FROM aux.del  } {4 5 6}
+do_execsql_test 4.2.3 { SELECT * FROM main.del } {}
+
+do_execsql_test 4.3.1 {
+  INSERT INTO aux.t1 VALUES('x', 'y', 'z');
+  UPDATE OR REPLACE aux.t1 SET c='z' WHERE a='a';
+} {}
+do_execsql_test 4.3.2 { SELECT * FROM aux.del  } {4 5 6 x y z}
+do_execsql_test 4.3.3 { SELECT * FROM main.del } {}
+
+#-------------------------------------------------------------------------
+#
+reset_db
+do_execsql_test 5.0 {
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c);
+  CREATE TABLE t2(a INTEGER PRIMARY KEY, b, c);
+  CREATE INDEX i1 ON t1(b);
+  INSERT INTO t1 VALUES(1, 2, 3), (4, 5, 6);
+  ANALYZE;
+  PRAGMA writable_schema = 1;
+  DELETE FROM sqlite_stat1;
+}
+db close
+forcecopy test.db test.db2
+sqlite3 db test.db -shared-schema 1
+execsql { ATTACH 'test.db2' AS aux }
+
+foreach {tn sql} {
+  1 { CREATE TABLE t3(x) }
+  2 { DROP TABLE t2 }
+  3 { CREATE INDEX i2 ON t2(b) }
+  4 { DROP INDEX i1 }
+  5 { ALTER TABLE t1 ADD COLUMN d }
+  6 { ALTER TABLE t1 RENAME TO t3 }
+  7 { ALTER TABLE t1 RENAME c TO d }
+} {
+  do_catchsql_test 5.1.$tn $sql {1 {attempt to modify read-only schema}}
+}
+
+do_execsql_test 5.2.1 { ANALYZE aux.t1 } {}
+do_execsql_test 5.2.2 { SELECT * FROM aux.sqlite_stat1  } {t1 i1 {2 1}}
+do_execsql_test 5.2.3 { SELECT * FROM main.sqlite_stat1 } {}
+
+do_test 5.3.0 {
+  sqlite3 db2 test.db2
+  db2 eval { 
+    PRAGMA writable_schema = 1;
+    DELETE FROM sqlite_stat1;
+  }
+} {}
+
+do_execsql_test 5.3.1 { SELECT * FROM aux.sqlite_stat1  } {}
+do_execsql_test 5.3.2 { ANALYZE aux } {}
+do_execsql_test 5.3.3 { SELECT * FROM aux.sqlite_stat1  } {t1 i1 {2 1}}
+do_execsql_test 5.3.4 { SELECT * FROM main.sqlite_stat1 } {}
+
+#-------------------------------------------------------------------------
+# Attempting to run ANALYZE when the required sqlite_statXX functions
+# are missing is an error (because it would modify the database schema).
+#
+reset_db
+do_execsql_test 5.4 {
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c);
+  CREATE TABLE t2(a INTEGER PRIMARY KEY, b, c);
+  CREATE INDEX i1 ON t1(b);
+  INSERT INTO t1 VALUES(1, 2, 3), (4, 5, 6);
+}
+db close
+sqlite3 db test.db -shared-schema 1
+foreach {tn sql} {
+  1 { ANALYZE }
+  2 { ANALYZE t1 }
+  3 { ANALYZE i1 }
+  4 { ANALYZE main }
+  5 { ANALYZE main.t1 }
+  6 { ANALYZE main.i1 }
+} {
+  do_catchsql_test 5.4.$tn $sql {1 {attempt to modify read-only schema}}
+}
+
+#-------------------------------------------------------------------------
+#
+reset_db
+do_execsql_test 6.0 {
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c);
+  CREATE VIEW v1 AS SELECT * FROM t1;
+}
+db close
+forcecopy test.db test.db2
+sqlite3 db test.db -shared-schema 1
+execsql { ATTACH 'test.db2' AS aux }
+
+do_execsql_test 6.1 {
+  INSERT INTO main.t1(a) VALUES(1), (2), (3);
+  INSERT INTO aux.t1(a) VALUES(4), (5), (6);
+  CREATE TEMP TABLE t2(i,t);
+  INSERT INTO t2 VALUES(2, 'two'), (5, 'five');
+}
+
+do_execsql_test 6.2 {
+  SELECT t FROM t2 WHERE i IN (SELECT a FROM aux.t1)
+} {five}
+do_execsql_test 6.3 {
+  SELECT t FROM t2 WHERE i IN (SELECT a FROM aux.v1)
+} {five}
+
+#-------------------------------------------------------------------------
+#
+reset_db
+do_execsql_test 7.0 {
+  CREATE TABLE p1(a PRIMARY KEY, b);
+  CREATE TABLE p2(a PRIMARY KEY, b);
+  CREATE TABLE c1(x REFERENCES p1 ON UPDATE CASCADE ON DELETE CASCADE);
+}
+
+db close
+forcecopy test.db test.db2
+sqlite3 db test.db -shared-schema 1
+execsql { ATTACH 'test.db2' AS aux }
+
+do_execsql_test 7.1 {
+  INSERT INTO aux.p1 VALUES(1, 'one');
+  INSERT INTO aux.p1 VALUES(2, 'two');
+  PRAGMA foreign_keys = on;
+}
+
+do_execsql_test 7.2 {
+  INSERT INTO aux.c1 VALUES(2);
+}
+
+do_execsql_test 7.3.1 {
+  PRAGMA foreign_keys = off;
+  INSERT INTO main.p2 SELECT * FROM aux.p1;
+}
+do_execsql_test 7.3.2 {
+  SELECT * FROM main.p2;
+} {1 one 2 two}
+
+do_execsql_test 7.3.3 {
+  INSERT INTO aux.p2 VALUES(1, 2);
+}
+
+do_execsql_test 7.3.4 {
+  SELECT main.p2.a FROM main.p2, aux.p2;
+} {1 2}
+
+do_execsql_test 7.3.5 {
+  SELECT * FROM main.p2, aux.p2;
+} {1 one 1 2   2 two 1 2}
+
+do_execsql_test 7.4 {
+  SELECT count(*) FROM aux.p2;
+} {1}
+
+
+finish_test
+
+

test/reuse2.test

@@ -0,0 +1,336 @@
+# 2017 August 9
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+#
+
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix reuse2
+
+ifcapable !sharedschema {
+  finish_test
+  return
+}
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(x INTEGER PRIMARY KEY, y UNIQUE, z);
+  CREATE INDEX i1 ON t1(z);
+  PRAGMA schema_version;
+} {2}
+
+do_test 1.2 {
+  catch { db close }
+  catch { db2 close }
+  sqlite3 db2 test.db -shared-schema 1
+  sqlite3 db  test.db -shared-schema 1
+} {}
+
+do_execsql_test -db db2 1.3.1 {
+  INSERT INTO t1 VALUES(1, 2, 3);
+}
+
+do_execsql_test -db db2 1.3.2 {
+  INSERT INTO t1 VALUES(4, 5, 6);
+}
+
+do_execsql_test 1.3.3 {
+  SELECT * FROM t1;
+} {1 2 3 4 5 6}
+
+#--------------------------------------------------------------------------
+reset_db
+ifcapable fts5 {
+  do_execsql_test 2.0 {
+    CREATE VIRTUAL TABLE ft USING fts5(c);
+    INSERT INTO ft VALUES('one two three');
+  }
+  db close
+  sqlite3 db test.db -shared-schema 1
+
+  do_execsql_test 2.1 {
+    SELECT * FROM ft
+  } {{one two three}}
+}
+
+#--------------------------------------------------------------------------
+reset_db
+do_execsql_test 3.0 {
+  CREATE TABLE t1(x INTEGER PRIMARY KEY, y UNIQUE, z);
+  CREATE INDEX i1 ON t1(z);
+  PRAGMA schema_version;
+} {2}
+
+do_test 3.1 {
+  sqlite3 db1 test.db -shared-schema 1
+  sqlite3 db2 test.db -shared-schema 1
+} {}
+
+do_execsql_test -db db1 3.2.1 { SELECT * FROM t1 }
+do_execsql_test -db db2 3.2.2 { SELECT * FROM t1 }
+
+register_schemapool_module db
+do_execsql_test 3.3 { 
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {nref=2 nschema=1 ndelete=0}
+
+sqlite3 db3 test.db -shared-schema 1
+register_schemapool_module db3
+
+do_execsql_test 3.5 { 
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {nref=2 nschema=1 ndelete=0}
+
+do_execsql_test -db db3 3.6 { 
+  SELECT * FROM t1;
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {nref=3 nschema=1 ndelete=0}
+
+do_execsql_test 3.7 { 
+  CREATE TABLE t2(x);
+}
+
+do_execsql_test 3.8 { 
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {nref=3 nschema=1 ndelete=0}
+
+do_execsql_test -db db1 3.9.1 { SELECT * FROM t1 }
+do_execsql_test 3.9.2 { 
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {nref=1 nschema=1 ndelete=0 nref=2 nschema=1 ndelete=0}
+
+do_execsql_test -db db2 3.10.1 { SELECT * FROM t1 }
+do_execsql_test 3.10.2 { 
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool ORDER BY 1;
+} {nref=1 nschema=1 ndelete=0 nref=2 nschema=1 ndelete=0}
+
+do_execsql_test -db db3 3.11.1 { SELECT * FROM t1 }
+do_execsql_test 3.11.2 { 
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {nref=3 nschema=1 ndelete=0}
+
+#--------------------------------------------------------------------------
+catch {db1 close}
+catch {db2 close}
+catch {db3 close}
+reset_db
+do_execsql_test 4.0.1 {
+  CREATE TABLE x1(a, b, c);
+  CREATE INDEX x1a ON x1(a);
+  CREATE INDEX x1b ON x1(b);
+}
+do_test 4.0.2 {
+  db close
+  for {set i 1} {$i < 6} {incr i} {
+    forcedelete test.db${i}-journal test.db${i}-wal test.db${i}-wal2 
+    forcecopy test.db test.db${i}
+  }
+  sqlite3 db  test.db
+  sqlite3 db2 test.db -shared-schema 1
+} {}
+
+register_schemapool_module db
+do_execsql_test 4.0.3 {
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {}
+
+do_test 4.1.1 {
+  execsql { 
+    ATTACH 'test.db1' AS db1; 
+    ATTACH 'test.db2' AS db2;
+    ATTACH 'test.db3' AS db3;
+    ATTACH 'test.db4' AS db4;
+    ATTACH 'test.db5' AS db5;
+  } db2
+} {}
+do_execsql_test 4.1.2 {
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {nref=1 nschema=1 ndelete=0}
+do_execsql_test -db db2 4.1.3 {
+  SELECT * FROM db3.x1
+}
+do_execsql_test 4.1.4 {
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {nref=2 nschema=1 ndelete=0}
+do_execsql_test -db db2 4.1.5 {
+  SELECT * FROM db2.x1
+}
+do_execsql_test 4.1.6 {
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {nref=3 nschema=1 ndelete=0}
+do_execsql_test -db db2 4.1.7 {
+  SELECT * FROM x1
+}
+do_execsql_test 4.1.8 {
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {nref=3 nschema=1 ndelete=0}
+
+do_test 4.2.1 {
+  catchsql { SELECT * FROM abc } db2
+} {1 {no such table: abc}}
+do_execsql_test 4.2.2 {
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {nref=6 nschema=1 ndelete=0}
+
+register_schemapool_module db2
+do_execsql_test -db db2 4.3.1 {
+  INSERT INTO x1 VALUES(1, 2, 3);
+  INSERT INTO db1.x1 VALUES(4, 5, 6);
+  INSERT INTO db2.x1 VALUES(7, 8, 9);
+  INSERT INTO db3.x1 VALUES(10, 11, 12);
+  INSERT INTO db4.x1 VALUES(13, 14, 15);
+  INSERT INTO db5.x1 VALUES(16, 17, 18);
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {nref=6 nschema=1 ndelete=0}
+
+do_execsql_test -db db2 4.3.2 {
+  SELECT * FROM db5.x1;
+  SELECT * FROM db4.x1;
+  SELECT * FROM db3.x1;
+  SELECT * FROM db2.x1;
+  SELECT * FROM db1.x1;
+  SELECT * FROM x1;
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {
+  16 17 18  13 14 15  10 11 12  7 8 9  4 5 6  1 2 3
+  nref=6 nschema=1 ndelete=0
+}
+
+do_execsql_test -db db2 4.3.3 {
+  UPDATE x1 SET a=a+10;
+  UPDATE db5.x1 SET a=a+10;
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {
+  nref=6 nschema=1 ndelete=0
+}
+
+do_execsql_test -db db2 4.3.4 {
+  SELECT * FROM db5.x1;
+  SELECT * FROM db4.x1;
+  SELECT * FROM db3.x1;
+  SELECT * FROM db2.x1;
+  SELECT * FROM db1.x1;
+  SELECT * FROM x1;
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {
+  26 17 18  13 14 15  10 11 12  7 8 9  4 5 6  11 2 3
+  nref=6 nschema=1 ndelete=0
+}
+
+do_execsql_test -db db2 4.3.5 {
+  DELETE FROM db3.x1;
+  DELETE FROM x1;
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {
+  nref=6 nschema=1 ndelete=0
+}
+
+do_execsql_test -db db2 4.3.6 {
+  SELECT * FROM db5.x1;
+  SELECT * FROM db4.x1;
+  SELECT * FROM db3.x1;
+  SELECT * FROM db2.x1;
+  SELECT * FROM db1.x1;
+  SELECT * FROM x1;
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {
+  26 17 18  13 14 15  7 8 9  4 5 6 
+  nref=6 nschema=1 ndelete=0
+}
+
+do_execsql_test -db db2 4.3.6 {
+  SELECT * FROM db5.x1, db4.x1, db1.x1;
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {26 17 18 13 14 15 4 5 6 nref=6 nschema=3 ndelete=0}
+
+#--------------------------------------------------------------------------
+# Test the incremental-blob API with REUSE_SCHEMA connections.
+#
+catch {db1 close}
+catch {db2 close}
+catch {db3 close}
+reset_db
+do_execsql_test 5.0.1 {
+  CREATE TABLE bbb(a INTEGER PRIMARY KEY, b);
+}
+db close
+do_test 5.0.2 {
+  sqlite3 db2 test.db -shared-schema 1
+  register_schemapool_module db2
+  for {set i 1} {$i<6} {incr i} {
+    forcedelete test.db${i}-journal test.db${i}-wal test.db${i}-wal2 
+    forcecopy test.db test.db${i}
+    sqlite3 db test.db${i}
+    db eval { INSERT INTO bbb VALUES(123, 'database_' || $i) }
+    db close
+    db2 eval "ATTACH 'test.db${i}' AS db${i}"
+  }
+  execsql {
+    SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+      FROM schemapool;
+  } db2
+} {nref=6 nschema=1 ndelete=0}
+
+do_test 5.1.1 {
+  set res [list]
+  for {set i 1} {$i<6} {incr i} {
+    set chan [db2 incrblob db${i} bbb b 123]
+    lappend res [gets $chan]
+    close $chan
+  }
+  set res
+} {database_1 database_2 database_3 database_4 database_5}
+
+do_execsql_test -db db2 5.1.2 {
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {nref=6 nschema=1 ndelete=0}
+
+do_test 5.2.1 {
+  sqlite3_table_column_metadata db2 main bbb a
+} {INTEGER BINARY 0 1 0}
+do_test 5.2.2 {
+  sqlite3_table_column_metadata db2 main bbb b
+} {{} BINARY 0 0 0}
+
+do_execsql_test -db db2 5.2.3 {
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {nref=6 nschema=1 ndelete=0}
+
+do_execsql_test -db db2 5.2.4 {
+  PRAGMA integrity_check;
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete
+  FROM schemapool;
+} {ok nref=6 nschema=1 ndelete=5}
+
+finish_test
+

test/reuse3.test

@@ -0,0 +1,355 @@
+# 2019 February 12
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+#
+
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix reuse3
+
+ifcapable !sharedschema {
+  finish_test
+  return
+}
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(x INTEGER PRIMARY KEY, y UNIQUE, z);
+  CREATE INDEX i1 ON t1(z);
+  CREATE TABLE t2(a);
+} {}
+
+db close
+sqlite3 db test.db -shared-schema 1
+
+do_execsql_test 1.1 {
+  CREATE TEMP VIEW v1 AS SELECT * FROM t1;
+  SELECT * FROM v1;
+}
+
+do_execsql_test 1.2 {
+  CREATE TEMP TRIGGER tr1 AFTER INSERT ON t1 BEGIN
+    INSERT INTO t2 VALUES(new.x);
+  END;
+}
+
+do_execsql_test 1.3 {
+  INSERT INTO t1 VALUES(1, 2, 3);
+}
+
+do_execsql_test 1.4 {
+  SELECT * FROM t2
+} {1}
+
+do_execsql_test 1.5 {
+  SELECT * FROM v1
+} {1 2 3}
+
+do_execsql_test 1.6 {
+  BEGIN;
+    DROP TRIGGER tr1;
+  ROLLBACK;
+}
+
+do_execsql_test 1.7 {
+  SELECT * FROM v1
+} {1 2 3}
+
+do_execsql_test 1.8 {
+  INSERT INTO t1 VALUES(4, 5, 6);
+  SELECT * FROM t2
+} {1 4}
+
+do_execsql_test 1.9 {
+  SELECT * FROM v1
+} {1 2 3 4 5 6}
+
+#-------------------------------------------------------------------------
+# Test error messages when parsing the schema with a REUSE_SCHEMA 
+# connection.
+reset_db
+do_execsql_test 2.0 {
+  CREATE TABLE x1(a, b, c);
+  CREATE TABLE y1(d, e, f);
+  PRAGMA writable_schema = 1;
+  UPDATE sqlite_master SET sql = 'CREATE TBL y1(d, e, f)' WHERE name = 'y1';
+}
+db close
+
+sqlite3 db test.db -shared-schema 1
+do_catchsql_test 2.1 {
+  SELECT * FROM x1;
+} {1 {malformed database schema (y1) - near "TBL": syntax error}}
+
+do_catchsql_test 2.2 {
+  SELECT * FROM x1;
+} {1 {malformed database schema (y1) - near "TBL": syntax error}}
+
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 3.0 {
+  CREATE TABLE x1(a, b, c);
+  CREATE INDEX i1 ON x1(a, b, c);
+  CREATE TRIGGER tr1 AFTER INSERT ON x1 BEGIN
+    SELECT 1, 2, 3, 4, 5;
+  END;
+  INSERT INTO x1 VALUES(1, 2, 3);
+}
+sqlite3 db1 test.db -shared-schema 1
+
+do_test 3.1 {
+  execsql { SELECT * FROM x1 } db1
+  set N [lindex [sqlite3_db_status db1 SCHEMA_USED 0] 1]
+  expr $N==$N
+} 1
+
+sqlite3 db2 test.db -shared-schema 1
+do_test 3.2 {
+  execsql { SELECT * FROM x1 } db2
+  set N2 [lindex [sqlite3_db_status db2 SCHEMA_USED 0] 1]
+  expr $N2>($N/2) && $N2<($N/2)+400
+} 1
+
+sqlite3 db3 test.db -shared-schema 1
+sqlite3 db4 test.db -shared-schema 1
+do_test 3.3 {
+  execsql { SELECT * FROM x1 } db3
+  execsql { SELECT * FROM x1 } db4
+  set N4 [lindex [sqlite3_db_status db2 SCHEMA_USED 0] 1]
+  set M [expr 2*($N-$N2)]
+  set {} {}
+} {}
+do_test 3.3.1 { expr {(($M / 4) + $N-$M)} } "#/$N4/"
+
+catch { db1 close }
+catch { db2 close }
+catch { db3 close }
+catch { db4 close }
+
+#-------------------------------------------------------------------------
+# 4.1 Test the REINDEX command.
+# 4.2 Test CREATE TEMP ... commands.
+#
+reset_db
+do_execsql_test 4.1.0 {
+  CREATE TABLE x1(a, b, c);
+  CREATE INDEX x1a ON x1(a);
+  CREATE INDEX x1b ON x1(b);
+  CREATE INDEX x1c ON x1(c);
+}
+db close
+sqlite3 db test.db -shared-schema 1
+
+do_execsql_test 4.1.1 {
+  REINDEX x1;
+  REINDEX x1a;
+  REINDEX x1b;
+  REINDEX x1c;
+  REINDEX;
+}
+
+do_test 4.1.2 {
+  for {set i 1} {$i < 5} {incr i} {
+    forcedelete test.db${i} test.db${i}-wal test.db${i}-journal
+    forcecopy test.db test.db${i}
+    execsql "ATTACH 'test.db${i}' AS db${i}"
+  }
+  register_schemapool_module db
+  set {} {}
+  execsql { 
+    SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete 
+    FROM schemapool 
+  }
+} {nref=5 nschema=1 ndelete=0}
+
+do_execsql_test 4.1.3 {
+  REINDEX  x1;
+  REINDEX  x1a;
+  REINDEX  x1b;
+  REINDEX  x1c;
+  REINDEX  db1.x1a;
+  REINDEX  db2.x1b;
+  REINDEX  db3.x1c;
+}
+
+do_execsql_test 4.1.4 {
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete 
+    FROM schemapool 
+} {nref=5 nschema=1 ndelete=28}
+
+#-------------------------------------------------------------------------
+db close
+sqlite3 db test.db -shared-schema 1
+register_schemapool_module db
+do_execsql_test 4.2.0 {
+  ATTACH 'test.db1' AS db1;
+  ATTACH 'test.db2' AS db2;
+  ATTACH 'test.db3' AS db3;
+  ATTACH 'test.db4' AS db4;
+
+  SELECT * FROM db1.x1;
+  SELECT * FROM db2.x1;
+  SELECT * FROM db3.x1;
+  SELECT * FROM db4.x1;
+}
+
+do_execsql_test 4.2.1 {
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete 
+    FROM schemapool; 
+} {nref=5 nschema=1 ndelete=0}
+
+do_execsql_test 4.2.2 {
+  CREATE TEMP TABLE t1(a, b, c);
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete 
+    FROM schemapool; 
+} {nref=5 nschema=1 ndelete=0}
+
+do_execsql_test 4.2.3 {
+  CREATE INDEX t1a ON t1(a);
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete 
+    FROM schemapool; 
+} {nref=5 nschema=1 ndelete=0}
+
+do_execsql_test 4.2.4 {
+  CREATE TRIGGER tr1 AFTER INSERT ON t1 BEGIN
+    SELECT 1,2,3,4;
+  END;
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete 
+    FROM schemapool; 
+} {nref=5 nschema=1 ndelete=0}
+
+do_execsql_test 4.2.5 {
+  DROP TABLE t1;
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete 
+    FROM schemapool; 
+} {nref=5 nschema=1 ndelete=0}
+
+do_execsql_test 4.2.6 {
+  CREATE TEMP TRIGGER tr1 AFTER INSERT ON db2.x1 BEGIN
+    SELECT 1,2,3,4;
+  END;
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete 
+    FROM schemapool; 
+} {nref=5 nschema=1 ndelete=0}
+
+do_execsql_test 4.2.7 {
+  DROP TRIGGER tr1;
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema, 'ndelete=' || nDelete 
+    FROM schemapool; 
+} {nref=5 nschema=1 ndelete=4}
+
+#--------------------------------------------------------------------------
+reset_db
+do_execsql_test 5.0 {
+  CREATE TABLE t1(a, b);
+  CREATE TABLE t2(a, b);
+  CREATE TABLE t3(a, b);
+}
+
+sqlite3 db2 test.db -shared-schema 1
+register_schemapool_module db2
+
+do_execsql_test 5.1 {
+  PRAGMA writable_schema = 1;
+  UPDATE sqlite_master SET sql='CREATE TABLE t3 a,b' WHERE name = 't3';
+}
+
+do_test 5.2 { 
+  catchsql { SELECT * FROM t1 } db2
+} {1 {malformed database schema (t3) - near "a": syntax error}}
+
+do_test 5.3 { 
+  catchsql { SELECT nref,nschema FROM schemapool } db2
+} {1 {malformed database schema (t3) - near "a": syntax error}}
+
+do_execsql_test 5.4 {
+  PRAGMA writable_schema = 1;
+  UPDATE sqlite_master SET sql='CREATE TABLE t3(a,b)' WHERE name = 't3';
+}
+
+do_test 5.5 { 
+  catchsql { SELECT nref,nschema FROM schemapool } db2
+} {0 {1 1}}
+
+db2 close
+db close
+do_test 5.6.1 {
+  forcedelete test.db2 test.db2-wal test.db2-journal
+  forcecopy test.db test.db2
+  sqlite3 db test.db
+  sqlite3 db2 test.db  -shared-schema 1
+  sqlite3 db3 test.db2 -shared-schema 1
+  register_schemapool_module db
+} {}
+
+do_execsql_test -db db2 5.6.2 { SELECT * FROM t1 }
+do_execsql_test -db db3 5.6.3 { SELECT * FROM t1 }
+do_execsql_test 5.6.4 {
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema FROM schemapool; 
+  CREATE TABLE t4(x);
+  DROP TABLE t4;
+} {nref=2 nschema=1}
+do_execsql_test -db db2 5.6.5 { SELECT * FROM t1 }
+do_execsql_test -db db3 5.6.6 { SELECT * FROM t1 }
+do_execsql_test 5.6.7 {
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema FROM schemapool; 
+  ATTACH 'test.db2' AS db2;
+  CREATE TABLE db2.t4(x);
+  DROP TABLE db2.t4;
+} {nref=1 nschema=1 nref=1 nschema=1}
+do_execsql_test -db db2 5.6.8 { SELECT * FROM t1 }
+do_execsql_test -db db3 5.6.9 { SELECT * FROM t1 }
+do_execsql_test 5.6.10 {
+  SELECT 'nref=' || nRef, 'nschema=' || nSchema FROM schemapool; 
+} {nref=2 nschema=1}
+
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 6.0 {
+  CREATE TABLE t1(a, b);
+  CREATE TABLE t2(a, b);
+  CREATE TABLE t3(a, b);
+}
+
+do_test 6.1 {
+  db close
+  sqlite3 db test.db -shared-schema 1
+  for {set i 1} {$i < 5} {incr i} {
+    set base "test.db$i"
+    set nm "aux$i"
+    forcedelete $base $base-wal $base-journal
+    forcecopy test.db $base
+    execsql "ATTACH '$base' AS $nm"
+  }
+} {}
+
+do_test 6.2 {
+  set N1 [lindex [sqlite3_db_status db SCHEMA_USED 0] 1]
+  set N2 [lindex [sqlite3_db_status db SCHEMA_USED 0] 1]
+  expr {$N1>0 && $N2>0 && $N1==$N2}
+} {1}
+
+do_test 6.3 {
+  execsql { SELECT * FROM main.t1 }
+  set N1 [lindex [sqlite3_db_status db SCHEMA_USED 0] 1]
+  set N2 [lindex [sqlite3_db_status db SCHEMA_USED 0] 1]
+  expr {$N1>0 && $N2>0 && $N1==$N2}
+} {1}
+
+do_test 6.4 {
+  execsql { SELECT * FROM aux1.t1 }
+  set N3 [lindex [sqlite3_db_status db SCHEMA_USED 0] 1]
+  set N4 [lindex [sqlite3_db_status db SCHEMA_USED 0] 1]
+  list $N3 $N4
+} "#/$N1 $N1/"
+
+finish_test
+

test/reuse4.test

@@ -0,0 +1,173 @@
+# 2019 February 12
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix reuse4
+
+ifcapable !sharedschema {
+  finish_test
+  return
+}
+
+foreach {tn sharedschema} {
+  1 0  
+  2 1  
+} {
+  reset_db
+
+  do_execsql_test 1.$tn.0 {
+    CREATE TABLE x1(a, b);
+    CREATE INDEX x1a ON x1(a);
+    CREATE INDEX x1b ON x1(b);
+    CREATE TABLE x2(a, b);
+  }
+  db close
+  
+  do_test 1.$tn.1 {
+    for {set i 1} {$i<4} {incr i} {
+      forcedelete test.db$i test.db$i-journal test.db$i-wal
+      forcecopy test.db test.db$i
+    }
+  
+    sqlite3 db test.db -shared-schema $sharedschema
+    for {set i 1} {$i<4} {incr i} {
+      execsql " ATTACH 'test.db$i' AS db$i "
+    }
+  } {}
+  
+  do_execsql_test 1.$tn.2 {
+    WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<10 )
+    INSERT INTO x1 SELECT i, i FROM s;
+  
+    INSERT INTO db3.x2 SELECT * FROM x1;
+    INSERT INTO db2.x1 SELECT * FROM db3.x2;
+    CREATE TEMP TRIGGER tr1 AFTER INSERT ON db2.x2 BEGIN
+      INSERT INTO x1 VALUES(new.a, new.b);
+    END;
+    INSERT INTO db2.x2 SELECT * FROM x1 WHERE a%2;
+    DELETE FROM x1 WHERE a<3;
+    INSERT INTO db3.x1 SELECT * FROM db2.x2;
+  
+    DETACH db3;
+    ATTACH 'test.db3' AS db3;
+  
+    UPDATE db3.x1 SET a=a-10 WHERE b NOT IN (SELECT b FROM db2.x2);
+  
+    CREATE TEMP TABLE x1(a, b);
+    INSERT INTO db2.x2 VALUES(50, 60), (60, 70), (80, 90);
+    ALTER TABLE x1 RENAME TO x2;
+    ALTER TABLE x2 ADD COLUMN c;
+    ALTER TABLE x2 RENAME a TO aaa;
+    DELETE FROM x1 WHERE b>8;
+    UPDATE db3.x2 SET b=b*10;
+  
+    BEGIN;
+      CREATE TEMP TABLE x5(x);
+      INSERT INTO x5 VALUES(1);
+    ROLLBACK;
+  
+    INSERT INTO main.x2 VALUES(123, 456);
+  }
+  
+  integrity_check 1.$tn.3
+  
+  do_execsql_test 1.$tn.4 {
+    SELECT * FROM main.x1; SELECT 'xxx';
+    SELECT * FROM main.x2; SELECT 'xxx';
+    SELECT * FROM temp.x2; SELECT 'xxx';
+  
+    SELECT * FROM db1.x1; SELECT 'xxx';
+    SELECT * FROM db1.x2; SELECT 'xxx';
+    SELECT * FROM db2.x1; SELECT 'xxx';
+    SELECT * FROM db2.x2; SELECT 'xxx';
+    SELECT * FROM db3.x1; SELECT 'xxx';
+    SELECT * FROM db3.x2; SELECT 'xxx';
+  } {
+    3 3 4 4 5 5 6 6 7 7 8 8 3 3 5 5 7 7 xxx 
+    123 456 xxx 
+    50 60 {} 60 70 {} 80 90 {} xxx
+    xxx
+    xxx
+    1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10 xxx
+    1 1 3 3 5 5 7 7 9 9 50 60 60 70 80 90 xxx
+    1 1 3 3  5 5 7 7 9 9 xxx 
+    1 10 2 20 3 30 4 40 5 50 6 60 7 70 8 80 9 90 10 100 xxx
+  }
+  
+  do_test 1.$tn.5.1 {
+    sqlite3 db2 test.db
+    db2 eval { CREATE TABLE x3(x) }
+  } {}
+  do_execsql_test 1.$tn.5.2 {
+    SELECT * FROM main.x1; SELECT 'xxx';
+    SELECT * FROM main.x2; SELECT 'xxx';
+    SELECT * FROM main.x3; SELECT 'xxx';
+  } {
+    3 3 4 4 5 5 6 6 7 7 8 8 3 3 5 5 7 7 xxx 
+    123 456 xxx 
+    xxx
+  }
+}
+
+#-------------------------------------------------------------------------
+# Test some PRAGMA statements with shared-schema connections.
+#
+reset_db
+do_execsql_test 2.0 {
+  CREATE TABLE t1(a, b, c);
+  CREATE INDEX t1abc ON t1(a, b, c);
+}
+
+foreach {tn pragma nSchema nDelete} {
+  1 "PRAGMA synchronous = OFF"     1 0
+  2 "PRAGMA cache_size = 200"      1 0
+  3 "PRAGMA aux2.integrity_check"  1 0
+  4 "PRAGMA      integrity_check"  1 5
+  5 "PRAGMA index_info=t1abc"      1 5
+  6 "PRAGMA aux3.index_info=t1abc" 1 0
+  7 "PRAGMA journal_mode"          1 0
+  8 "PRAGMA aux2.wal_checkpoint"   1 0
+  9 "PRAGMA wal_checkpoint"        1 0
+} {
+  do_test 2.$tn.1 {
+    catch { db close }
+    catch { db2 close }
+    for {set i 1} {$i < 6} {incr i} {
+      forcedelete "test.db$i" "test.db${i}-wal" "test.db${i}-journal"
+      forcecopy test.db test.db$i
+    }
+    sqlite3 db2 test.db -shared-schema 1
+    for {set i 1} {$i < 6} {incr i} {
+      execsql "ATTACH 'test.db$i' AS aux$i" db2
+    }
+  } {}
+
+  sqlite3 db test.db
+  register_schemapool_module db
+
+  do_test 2.$tn.2 {
+    execsql $pragma db2
+    execsql { SELECT 'nschema='||nschema, 'ndelete='||nDelete FROM schemapool }
+  } "nschema=$nSchema ndelete=$nDelete"
+
+  do_test 2.$tn.3 {
+    execsql {
+      SELECT * FROM main.t1,aux1.t1,aux2.t1,aux3.t1,aux4.t1,aux5.t1
+    } db2
+    execsql { SELECT 'nschema=' || nschema, 'nref=' || nref FROM schemapool }
+  } "nschema=6 nref=6"
+}
+
+finish_test
+

test/reuse5.test

@@ -0,0 +1,125 @@
+# 2019 February 26
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix reuse5
+set CLI [test_find_cli]
+
+ifcapable !sharedschema {
+  finish_test
+  return
+}
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(x, y);
+  CREATE TABLE t2(a, b, c);
+  CREATE INDEX t1x ON t1(x);
+  CREATE INDEX t1y ON t1(y);
+  CREATE VIEW v1 AS SELECT * FROM t2;
+}
+
+foreach {tn sql out1 out2} {
+  1 {
+    CREATE TABLE t1(x, y);
+    CREATE TABLE t2(a, b, c);
+    CREATE INDEX t1x ON t1(x);
+    CREATE INDEX t1y ON t1(y);
+    CREATE VIEW v1 AS SELECT * FROM t2;
+  } {
+    test.db2 is compatible
+  } {}
+
+  2 {
+    CREATE TABLE t1(x, y);
+    CREATE TABLE t2(a, b, c);
+    CREATE INDEX t1x ON t1(x);
+    CREATE INDEX t1y ON t1(y);
+    CREATE VIEW v1 AS SELECT * FROM t2;
+    CREATE TABLE x1(x);
+    DROP TABLE x1;
+  } {
+    test.db2 is NOT compatible (schema cookie)
+  } {
+    Fixing test.db2... test.db2 is compatible
+  }
+
+  3 {
+    CREATE TABLE t1(x, y);
+    CREATE TABLE t2(a, b, c);
+    CREATE INDEX t1y ON t1(y);
+    CREATE VIEW v1 AS SELECT * FROM t2;
+  } {
+    test.db2 is NOT compatible (objects)
+  } {}
+
+  4 {
+    CREATE TABLE t1(x, y);
+    CREATE TABLE t2(a, b, c);
+    CREATE INDEX t1x ON t1(X);
+    CREATE INDEX t1y ON t1(y);
+    CREATE VIEW v1 AS SELECT * FROM t2;
+  } {
+    test.db2 is NOT compatible (SQL)
+  } {}
+
+  5 {
+    CREATE TABLE t1(x, y);
+    CREATE TABLE t2(a, b, c);
+    CREATE INDEX t1y ON t1(y);
+    CREATE INDEX t1x ON t1(x);
+    CREATE VIEW v1 AS SELECT * FROM t2;
+  } {
+    test.db2 is NOT compatible (root pages)
+  } {
+    Fixing test.db2... test.db2 is compatible
+  }
+
+  6 {
+    CREATE TABLE t1(x, y);
+    CREATE TABLE t2(a, b, c);
+    CREATE INDEX t1x ON t1(x);
+    CREATE INDEX t1y ON t1(y);
+    CREATE VIEW v1 AS SELECT * FROM t2;
+    DROP INDEX t1x;
+    CREATE INDEX t1x ON t1(x);
+  } {
+    test.db2 is NOT compatible (order of sqlite_master rows)
+  } {
+    Fixing test.db2... test.db2 is compatible
+  }
+
+} {
+  forcedelete test.db2
+  sqlite3 db2 test.db2
+  db2 eval $sql
+  db2 close
+
+  if {$out2==""} {set out2 $out1}
+
+  do_test 1.$tn.1 {
+    catchcmd test.db ".shared-schema check test.db2"
+  } [list 0 [string trim $out1]]
+
+  do_test 1.$tn.2 {
+    catchcmd test.db ".shared-schema fix test.db2"
+  } [list 0 [string trim $out2]]
+
+  do_test 1.$tn.3 {
+    catchcmd test.db2 "PRAGMA integrity_check"
+  } [list 0 ok]
+}
+
+
+finish_test
+

test/reuse6.test

@@ -0,0 +1,143 @@
+# 2019 February 26
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix reuse6
+
+ifcapable !sharedschema {
+  finish_test
+  return
+}
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(x, y);
+  CREATE TABLE t2(a, b, c);
+  CREATE INDEX t1x ON t1(x);
+  CREATE INDEX t1y ON t1(y);
+  CREATE VIEW v1 AS SELECT * FROM t2;
+
+  INSERT INTO t1 VALUES(1, 2), (3, 4), (5, 6);
+  INSERT INTO t2 VALUES('a', 'b', 'c'), ('d', 'e', 'f'), ('g', 'h', 'i');
+
+  ATTACH 'test.db2' AS aux;
+  CREATE TABLE t3(i, ii);
+  INSERT INTO t3 VALUES(10, 20);
+}
+
+sqlite3 db1 test.db -shared-schema 1
+sqlite3 db2 test.db -shared-schema 1
+
+do_execsql_test -db db1 1.1 {
+  ATTACH 'test.db2' AS aux;
+}
+
+do_test 1.2 {
+  execsql {SELECT * FROM t3} db1
+} {10 20}
+
+do_execsql_test -db db2 1.3 {
+  ATTACH 'test.db2' AS aux;
+}
+
+do_test 1.3 {
+  execsql {SELECT * FROM t3} db1
+} {10 20}
+
+do_execsql_test -db db2 1.5 {
+  SELECT * FROM t3;
+} {10 20}
+
+do_test 1.6 {
+  execsql {SELECT * FROM t3} db1
+} {10 20}
+
+db1 close
+db2 close
+
+#-------------------------------------------------------------------------
+reset_db
+forcedelete test.db2
+forcedelete test.db3
+do_execsql_test 2.0 {
+  CREATE TABLE t1(x, y);
+  ATTACH 'test.db2' AS aux2;
+  CREATE TABLE aux2.t2(x, y);
+  ATTACH 'test.db3' AS aux3;
+  CREATE TABLE aux3.t3(x, y);
+}
+
+sqlite3 db1 test.db -shared-schema 1
+do_execsql_test -db db1 2.1 {
+  ATTACH 'test.db2' AS aux2;
+  ATTACH 'test.db3' AS aux3;
+}
+
+do_test 2.2.1 {
+  catchsql { SELECT * FROM aux2.nosuchtable } db1
+} {1 {no such table: aux2.nosuchtable}}
+do_test 2.2.2 {
+  sqlite3_errcode db1
+} {SQLITE_ERROR}
+db1 close
+
+#-------------------------------------------------------------------------
+reset_db
+forcedelete test.db2
+ifcapable fts5 {
+  do_execsql_test 3.0 {
+    CREATE VIRTUAL TABLE ft USING fts5(a, b);
+    ATTACH 'test.db2' AS aux;
+    CREATE TABLE aux.t1(x, y, z);
+  }
+
+  sqlite3 db1 test.db -shared-schema 1
+  do_execsql_test -db db1 3.1 {
+    ATTACH 'test.db2' AS aux;
+  }
+
+  do_execsql_test -db db1 3.2 {
+    SELECT * FROM main.ft, aux.t1;
+  }
+  db1 close
+}
+
+#-------------------------------------------------------------------------
+reset_db
+forcedelete test.db2
+ifcapable fts5 {
+  do_execsql_test 4.0 {
+    CREATE VIRTUAL TABLE ft USING fts5(a, b);
+  }
+  forcecopy test.db test.db2
+
+  sqlite3 db1 test.db -shared-schema 1
+  do_execsql_test -db db1 4.1 {
+    ATTACH 'test.db2' AS aux;
+    SELECT * FROM main.ft;
+    SELECT * FROM aux.ft;
+  }
+
+  do_execsql_test -db db1 4.2 {
+    SELECT * FROM main.ft, aux.ft
+  }
+}
+
+
+
+
+
+
+
+finish_test
+

test/reusefault.test

@@ -0,0 +1,54 @@
+# 2019 February 12
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix reusefault
+
+ifcapable !sharedschema {
+  finish_test
+  return
+}
+
+do_execsql_test 1.0 {
+  PRAGMA cache_size = 10;
+  CREATE TABLE t1(a UNIQUE, b UNIQUE);
+  INSERT INTO t1 VALUES(1, 2), (3, 4);
+}
+faultsim_save_and_close
+
+do_faultsim_test 1.1 -prep {
+  faultsim_restore
+  sqlite3 db test.db -shared-schema 1
+} -body {
+  execsql { SELECT * FROM t1 }
+} -test {
+  faultsim_test_result {0 {1 2 3 4}}
+}
+
+do_faultsim_test 1.2 -prep {
+  faultsim_restore
+  sqlite3 db test.db -shared-schema 1
+  execsql { SELECT * FROM t1 }
+  sqlite3 db2 test.db
+  db2 eval {CREATE TABLE a(a)}
+  db2 close
+} -body {
+  execsql { SELECT  * FROM t1 }
+} -test {
+  faultsim_test_result {0 {1 2 3 4}}
+}
+
+
+finish_test
+

test/subtype1.test

@@ -53,7 +53,25 @@ do_execsql_test subtype1-231 {
   WITH t4(a) AS NOT MATERIALIZED (SELECT json(1)) SELECT subtype(a) FROM t4;
 } {0}
 
-
+# 2023-03-01
+# https://sqlite.org/forum/forumpost/37dd14a538
+# 
+# Additional tests to show that subtypes do not traverse subquery boundaries.
+#
+do_execsql_test subtype1-300 {
+  CREATE TABLE t0(c0);
+  INSERT INTO t0 VALUES ('1');
+  CREATE VIEW v0(c0) AS SELECT CASE WHEN 1 THEN json_patch('1', '1') END 
+                        FROM t0 GROUP BY t0.c0;
+  SELECT * FROM v0 WHERE json_quote(v0.c0) != '1';
+} {1}
+do_execsql_test subtype1-310 {
+  SELECT *, json_quote(y) FROM (SELECT +json('1') AS y);
+} {1 {"1"}}
+do_execsql_test subtype1-320 {
+  SELECT *, json_quote(y) FROM (SELECT +json('1') AS y)
+   WHERE json_quote(y)='"1"';
+} {1 {"1"}}
 
 
 finish_test

test/tclsqlite.test

@@ -26,6 +26,9 @@ set testprefix tcl
 # Check the error messages generated by tclsqlite
 #
 set r "sqlite_orig HANDLE ?FILENAME? ?-vfs VFSNAME? ?-readonly BOOLEAN? ?-create BOOLEAN? ?-nofollow BOOLEAN? ?-nomutex BOOLEAN? ?-fullmutex BOOLEAN? ?-uri BOOLEAN?"
+ifcapable sharedschema {
+  append r " ?-shared-schema BOOLEAN?"
+}
 if {[sqlite3 -has-codec]} {
   append r " ?-key CODECKEY?"
 }

test/tester.tcl

@@ -949,6 +949,29 @@ proc normalize_list {L} {
   set L2
 }
 
+# Run SQL and verify that the number of "vmsteps" required is greater
+# than or less than some constant.
+#
+proc do_vmstep_test {tn sql nstep {res {}}} {
+  uplevel [list do_execsql_test $tn.0 $sql $res]
+
+  set vmstep [db status vmstep]
+  if {[string range $nstep 0 0]=="+"} {
+    set body "if {$vmstep<$nstep} {
+      error \"got $vmstep, expected more than [string range $nstep 1 end]\"
+    }"
+  } else {
+    set body "if {$vmstep>$nstep} {
+      error \"got $vmstep, expected less than $nstep\"
+    }"
+  }
+
+  # set name "$tn.vmstep=$vmstep,expect=$nstep"
+  set name "$tn.1"
+  uplevel [list do_test $name $body {}]
+}
+
+
 # Either:
 #
 #   do_execsql_test TESTNAME SQL ?RES?

test/threadtest3.c

@@ -38,7 +38,7 @@
 #define SEL(e) ((e)->iLine = ((e)->rc ? (e)->iLine : __LINE__))
 
 /* Database functions */
-#define opendb(w,x,y,z)         (SEL(w), opendb_x(w,x,y,z))
+#define opendb(w,x,y,z,f)       (SEL(w), opendb_x(w,x,y,z,f))
 #define closedb(y,z)            (SEL(y), closedb_x(y,z))
 
 /* Functions to execute SQL */
@@ -545,11 +545,14 @@ static void opendb_x(
   Error *pErr,                    /* IN/OUT: Error code */
   Sqlite *pDb,                    /* OUT: Database handle */
   const char *zFile,              /* Database file name */
-  int bDelete                     /* True to delete db file before opening */
+  int bDelete,                    /* True to delete db file before opening */
+  int flags
 ){
   if( pErr->rc==SQLITE_OK ){
     int rc;
-    int flags = SQLITE_OPEN_CREATE | SQLITE_OPEN_READWRITE | SQLITE_OPEN_URI;
+    if( flags==0 ){
+      flags = SQLITE_OPEN_CREATE | SQLITE_OPEN_READWRITE | SQLITE_OPEN_URI;
+    }
     if( bDelete ) unlink(zFile);
     rc = sqlite3_open_v2(zFile, &pDb->db, flags, 0);
     if( rc ){
@@ -985,7 +988,7 @@ static char *walthread1_thread(int iTid, void *pArg){
   Sqlite db = {0};                /* SQLite database connection */
   int nIter = 0;                  /* Iterations so far */
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
   while( !timetostop(&err) ){
     const char *azSql[] = {
       "SELECT md5sum(x) FROM t1 WHERE rowid != (SELECT max(rowid) FROM t1)",
@@ -1024,7 +1027,7 @@ static char *walthread1_ckpt_thread(int iTid, void *pArg){
   Sqlite db = {0};                /* SQLite database connection */
   int nCkpt = 0;                  /* Checkpoints so far */
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
   while( !timetostop(&err) ){
     sqlite3_sleep(500);
     execsql(&err, &db, "PRAGMA wal_checkpoint");
@@ -1043,7 +1046,7 @@ static void walthread1(int nMs){
   Threadset threads = {0};        /* Test threads */
   int i;                          /* Iterator variable */
 
-  opendb(&err, &db, "test.db", 1);
+  opendb(&err, &db, "test.db", 1, 0);
   sql_script(&err, &db,
       "PRAGMA journal_mode = WAL;"
       "CREATE TABLE t1(x PRIMARY KEY);"
@@ -1076,7 +1079,7 @@ static char *walthread2_thread(int iTid, void *pArg){
     int journal_exists = 0;
     int wal_exists = 0;
 
-    opendb(&err, &db, "test.db", 0);
+    opendb(&err, &db, "test.db", 0, 0);
 
     sql_script(&err, &db, zJournal);
     clear_error(&err, SQLITE_BUSY);
@@ -1106,7 +1109,7 @@ static void walthread2(int nMs){
   Sqlite db = {0};
   Threadset threads = {0};
 
-  opendb(&err, &db, "test.db", 1);
+  opendb(&err, &db, "test.db", 1, 0);
   sql_script(&err, &db, "CREATE TABLE t1(x INTEGER PRIMARY KEY, y UNIQUE)");
   closedb(&err, &db);
 
@@ -1126,7 +1129,7 @@ static char *walthread3_thread(int iTid, void *pArg){
   i64 iNextWrite;                 /* Next value this thread will write */
   int iArg = PTR2INT(pArg);
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
   sql_script(&err, &db, "PRAGMA wal_autocheckpoint = 10");
 
   iNextWrite = iArg+1;
@@ -1163,7 +1166,7 @@ static void walthread3(int nMs){
   Threadset threads = {0};
   int i;
 
-  opendb(&err, &db, "test.db", 1);
+  opendb(&err, &db, "test.db", 1, 0);
   sql_script(&err, &db, 
       "PRAGMA journal_mode = WAL;"
       "CREATE TABLE t1(cnt PRIMARY KEY, sum1, sum2);"
@@ -1186,7 +1189,7 @@ static char *walthread4_reader_thread(int iTid, void *pArg){
   Error err = {0};                /* Error code and message */
   Sqlite db = {0};                /* SQLite database connection */
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
   while( !timetostop(&err) ){
     integrity_check(&err, &db);
   }
@@ -1201,7 +1204,7 @@ static char *walthread4_writer_thread(int iTid, void *pArg){
   Sqlite db = {0};                /* SQLite database connection */
   i64 iRow = 1;
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
   sql_script(&err, &db, "PRAGMA wal_autocheckpoint = 15;");
   while( !timetostop(&err) ){
     execsql_i64(
@@ -1221,7 +1224,7 @@ static void walthread4(int nMs){
   Sqlite db = {0};
   Threadset threads = {0};
 
-  opendb(&err, &db, "test.db", 1);
+  opendb(&err, &db, "test.db", 1, 0);
   sql_script(&err, &db, 
       "PRAGMA journal_mode = WAL;"
       "CREATE TABLE t1(a INTEGER PRIMARY KEY, b UNIQUE);"
@@ -1241,7 +1244,7 @@ static char *walthread5_thread(int iTid, void *pArg){
   Sqlite db = {0};                /* SQLite database connection */
   i64 nRow;
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
   nRow = execsql_i64(&err, &db, "SELECT count(*) FROM t1");
   closedb(&err, &db);
 
@@ -1254,7 +1257,7 @@ static void walthread5(int nMs){
   Sqlite db = {0};
   Threadset threads = {0};
 
-  opendb(&err, &db, "test.db", 1);
+  opendb(&err, &db, "test.db", 1, 0);
   sql_script(&err, &db, 
       "PRAGMA wal_autocheckpoint = 0;"
       "PRAGMA page_size = 1024;"
@@ -1345,7 +1348,7 @@ static void cgt_pager_1(int nMs){
   Error err = {0};
   Sqlite db = {0};
 
-  opendb(&err, &db, "test.db", 1);
+  opendb(&err, &db, "test.db", 1, 0);
   sql_script(&err, &db,
       "PRAGMA cache_size = 2000;"
       "PRAGMA page_size = 1024;"
@@ -1374,7 +1377,7 @@ static char *dynamic_triggers_1(int iTid, void *pArg){
   int nDrop = 0;
   int nCreate = 0;
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
   while( !timetostop(&err) ){
     int i;
 
@@ -1427,7 +1430,7 @@ static char *dynamic_triggers_2(int iTid, void *pArg){
   int nInsert = 0;
   int nDelete = 0;
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
   while( !timetostop(&err) ){
     do {
       iVal = (iVal+1)%100;
@@ -1452,7 +1455,7 @@ static void dynamic_triggers(int nMs){
   Sqlite db = {0};
   Threadset threads = {0};
 
-  opendb(&err, &db, "test.db", 1);
+  opendb(&err, &db, "test.db", 1, 0);
   sql_script(&err, &db, 
       "PRAGMA page_size = 1024;"
       "PRAGMA journal_mode = WAL;"
@@ -1492,6 +1495,7 @@ static void dynamic_triggers(int nMs){
 #include "tt3_lookaside1.c"
 #include "tt3_vacuum.c"
 #include "tt3_stress.c"
+#include "tt3_reuseschema.c"
 #include "tt3_shared.c"
 
 int main(int argc, char **argv){
@@ -1517,6 +1521,7 @@ int main(int argc, char **argv){
     { vacuum1,             "vacuum1", 10000 },
     { stress1,             "stress1", 10000 },
     { stress2,             "stress2", 60000 },
+    { reuse_schema_1,      "reuse_schema_1", 20000 },
     { shared1,             "shared1", 10000 },
   };
   static char *substArgv[] = { 0, "*", 0 };

test/tkt-99378177930f87bd.test

@@ -176,4 +176,19 @@ do_execsql_test tkt-99378-310 {
          );
 } {1 2}
 
+# 2023-03-04 https://sqlite.org/forum/forumpost/a68313d054
+#
+do_execsql_test tkt-99378-400 {
+  DROP TABLE t1;
+  CREATE TABLE t0(w);
+  INSERT INTO t0(w) VALUES(1);
+  CREATE TABLE t1(x);
+  INSERT INTO t1(x) VALUES(1);
+  CREATE INDEX t1x ON t1(x > 0);
+  CREATE VIEW t2(y) AS SELECT avg(w) FROM t0 GROUP BY w>1;
+  CREATE VIEW t3(z) AS SELECT count(*) FROM t2 WHERE y BETWEEN 0 and 0;
+  SELECT count(*) FROM t1 NOT INDEXED WHERE (SELECT z FROM t3);
+  SELECT count(*) FROM t1 INDEXED BY t1x WHERE (SELECT z FROM t3);
+} {0 0}
+
 finish_test

test/tt3_checkpoint.c

@@ -70,7 +70,7 @@ static char *checkpoint_starvation_reader(int iTid, void *pArg){
   Error err = {0};
   Sqlite db = {0};
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
   while( !timetostop(&err) ){
     i64 iCount1, iCount2;
     sql_script(&err, &db, "BEGIN");
@@ -96,7 +96,7 @@ static void checkpoint_starvation_main(int nMs, CheckpointStarvationCtx *p){
   int nInsert = 0;
   int i;
 
-  opendb(&err, &db, "test.db", 1);
+  opendb(&err, &db, "test.db", 1, 0);
   sql_script(&err, &db, 
       "PRAGMA page_size = 1024;"
       "PRAGMA journal_mode = WAL;"

test/tt3_index.c

@@ -19,7 +19,7 @@ static char *create_drop_index_thread(int iTid, void *pArg){
   Sqlite db = {0};                /* SQLite database connection */
 
   while( !timetostop(&err) ){
-    opendb(&err, &db, "test.db", 0);
+    opendb(&err, &db, "test.db", 0, 0);
 
     sql_script(&err, &db, 
       "DROP INDEX IF EXISTS i1;"
@@ -51,7 +51,7 @@ static void create_drop_index_1(int nMs){
   Sqlite db = {0};
   Threadset threads = {0};
 
-  opendb(&err, &db, "test.db", 1);
+  opendb(&err, &db, "test.db", 1, 0);
   sql_script(&err, &db, 
      "CREATE TABLE t11(a, b, c, d);"
      "WITH data(x) AS (SELECT 1 UNION ALL SELECT x+1 FROM data WHERE x<100) "

test/tt3_lookaside1.c

@@ -22,7 +22,7 @@ static char *lookaside1_thread_reader(int iTid, void *pArg){
   Error err = {0};                /* Error code and message */
   Sqlite db = {0};                /* SQLite database connection */
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
 
   while( !timetostop(&err) ){
     sqlite3_stmt *pStmt = 0;
@@ -47,7 +47,7 @@ static char *lookaside1_thread_writer(int iTid, void *pArg){
   Error err = {0};                /* Error code and message */
   Sqlite db = {0};                /* SQLite database connection */
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
 
   do{
     sql_script(&err, &db, 
@@ -68,7 +68,7 @@ static void lookaside1(int nMs){
   Sqlite db = {0};
   Threadset threads = {0};
 
-  opendb(&err, &db, "test.db", 1);
+  opendb(&err, &db, "test.db", 1, 0);
   sql_script(&err, &db, 
      "CREATE TABLE t1(x PRIMARY KEY) WITHOUT ROWID;"
      "WITH data(x,y) AS ("

test/tt3_reuseschema.c

@@ -0,0 +1,73 @@
+/*
+** 2014 December 9
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+**     reuse_schema_1
+*/
+
+
+static char *reuse_schema_thread(int iTid, void *pArg){
+  Error err = {0};                /* Error code and message */
+  Sqlite db = {0};                /* SQLite database connection */
+  int iRep = 0;
+
+  while( !timetostop(&err) ){
+    int f = SQLITE_OPEN_READWRITE|SQLITE_OPEN_SHARED_SCHEMA;
+    opendb(&err, &db, "test.db", 0, f);
+
+    execsql_i64(&err, &db, "SELECT count(*) FROM t1");
+    sql_script(&err, &db, "ATTACH 'test.db2' AS aux");
+    execsql_i64(&err, &db, "SELECT count(*) FROM t1");
+
+    closedb(&err, &db);
+    iRep++;
+  }
+
+  print_and_free_err(&err);
+  return sqlite3_mprintf("%d", iRep);
+}
+
+static void reuse_schema_1(int nMs){
+  Error err = {0};
+  Sqlite db = {0};
+  Threadset threads = {0};
+
+  opendb(&err, &db, "test.db", 1, 0);
+  sql_script(&err, &db, 
+     "CREATE TABLE t1(a, b, c, d);"
+     "WITH data(x) AS (SELECT 1 UNION ALL SELECT x+1 FROM data WHERE x<100) "
+     "INSERT INTO t1 SELECT x,x,x,x FROM data;"
+  );
+  closedb(&err, &db);
+  opendb(&err, &db, "test.db2", 1, 0);
+  sql_script(&err, &db, 
+#ifdef SQLITE_ENABLE_FTS5
+     "CREATE VIRTUAL TABLE t2 USING fts5(a, b, c, d);"
+#else
+     "CREATE TABLE t2(a, b, c, d);"
+#endif
+     "WITH data(x) AS (SELECT 1 UNION ALL SELECT x+1 FROM data WHERE x<100) "
+     "INSERT INTO t2 SELECT x*2,x*2,x*2,x*2 FROM data;"
+  );
+  closedb(&err, &db);
+
+  setstoptime(&err, nMs);
+
+  launch_thread(&err, &threads, reuse_schema_thread, 0);
+  launch_thread(&err, &threads, reuse_schema_thread, 0);
+  launch_thread(&err, &threads, reuse_schema_thread, 0);
+  launch_thread(&err, &threads, reuse_schema_thread, 0);
+  launch_thread(&err, &threads, reuse_schema_thread, 0);
+
+  join_all_threads(&err, &threads);
+  sqlite3_enable_shared_cache(0);
+  print_and_free_err(&err);
+}

test/tt3_stress.c

@@ -21,7 +21,7 @@ static char *stress_thread_1(int iTid, void *pArg){
   Error err = {0};                /* Error code and message */
   Sqlite db = {0};                /* SQLite database connection */
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
   while( !timetostop(&err) ){
     sql_script(&err, &db, "CREATE TABLE IF NOT EXISTS t1(a PRIMARY KEY, b)");
     clear_error(&err, SQLITE_LOCKED);
@@ -40,7 +40,7 @@ static char *stress_thread_2(int iTid, void *pArg){
   Error err = {0};                /* Error code and message */
   Sqlite db = {0};                /* SQLite database connection */
   while( !timetostop(&err) ){
-    opendb(&err, &db, "test.db", 0);
+    opendb(&err, &db, "test.db", 0, 0);
     sql_script(&err, &db, "SELECT * FROM sqlite_schema;");
     clear_error(&err, SQLITE_LOCKED);
     closedb(&err, &db);
@@ -59,7 +59,7 @@ static char *stress_thread_3(int iTid, void *pArg){
   int i1 = 0;
   int i2 = 0;
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
   while( !timetostop(&err) ){
     sql_script(&err, &db, "SELECT * FROM t1 ORDER BY a;");
     i1++;
@@ -82,11 +82,11 @@ static char *stress_thread_4(int iTid, void *pArg){
   int i2 = 0;
   int iArg = PTR2INT(pArg);
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
   while( !timetostop(&err) ){
     if( iArg ){
       closedb(&err, &db);
-      opendb(&err, &db, "test.db", 0);
+      opendb(&err, &db, "test.db", 0, 0);
     }
     sql_script(&err, &db, 
         "WITH loop(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM loop LIMIT 200) "
@@ -113,12 +113,12 @@ static char *stress_thread_5(int iTid, void *pArg){
   int i1 = 0;
   int i2 = 0;
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
   while( !timetostop(&err) ){
     i64 i = (i1 % 4);
     if( iArg ){
       closedb(&err, &db);
-      opendb(&err, &db, "test.db", 0);
+      opendb(&err, &db, "test.db", 0, 0);
     }
     execsql(&err, &db, "DELETE FROM t1 WHERE (rowid % 4)==:i", &i);
     i1++;
@@ -265,7 +265,7 @@ static char *stress2_workload19(int iTid, void *pArg){
   Sqlite db = {0};                /* SQLite database connection */
   const char *zDb = (const char*)pArg;
   while( !timetostop(&err) ){
-    opendb(&err, &db, zDb, 0);
+    opendb(&err, &db, zDb, 0, 0);
     sql_script(&err, &db, "SELECT * FROM sqlite_schema;");
     clear_error(&err, SQLITE_LOCKED);
     closedb(&err, &db);
@@ -290,7 +290,7 @@ static char *stress2_thread_wrapper(int iTid, void *pArg){
 
   while( !timetostop(&err) ){
     int cnt;
-    opendb(&err, &db, pCtx->zDb, 0);
+    opendb(&err, &db, pCtx->zDb, 0, 0);
     for(cnt=0; err.rc==SQLITE_OK && cnt<STRESS2_TABCNT; cnt++){
       pCtx->xProc(&err, &db, i1);
       i2 += (err.rc==SQLITE_OK);
@@ -342,7 +342,7 @@ static void stress2(int nMs){
   Threadset threads = {0};
 
   /* To make sure the db file is empty before commencing */
-  opendb(&err, &db, zDb, 1);
+  opendb(&err, &db, zDb, 1, 0);
   sql_script(&err, &db, 
       "CREATE TABLE IF NOT EXISTS t0(x PRIMARY KEY, y, z);"
       "CREATE INDEX IF NOT EXISTS i0 ON t0(y);"

test/tt3_vacuum.c

@@ -25,7 +25,7 @@ static char *vacuum1_thread_writer(int iTid, void *pArg){
   Sqlite db = {0};                /* SQLite database connection */
   i64 i = 0;
 
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
   while( !timetostop(&err) ){
     i++;
 
@@ -52,7 +52,7 @@ static char *vacuum1_thread_writer(int iTid, void *pArg){
 static char *vacuum1_thread_vacuumer(int iTid, void *pArg){
   Error err = {0};                /* Error code and message */
   Sqlite db = {0};                /* SQLite database connection */
-  opendb(&err, &db, "test.db", 0);
+  opendb(&err, &db, "test.db", 0, 0);
 
   do{
     sql_script(&err, &db, "VACUUM");
@@ -69,7 +69,7 @@ static void vacuum1(int nMs){
   Sqlite db = {0};
   Threadset threads = {0};
 
-  opendb(&err, &db, "test.db", 1);
+  opendb(&err, &db, "test.db", 1, 0);
   sql_script(&err, &db, 
      "CREATE TABLE t1(x PRIMARY KEY, y BLOB);"
      "CREATE INDEX i1 ON t1(y);"

test/update.test

@@ -732,4 +732,37 @@ do_execsql_test update-20.30 {
   PRAGMA integrity_check;
 } {ok}
 
+# 2023-03-16 https://sqlite.org/forum/forumpost/0007d1fdb1
+# A subquery in the WHERE clause of an UPDATE and behind a
+# short-circuit evaluation caused problems because multi-row
+# single-pass was selected.
+#
+# Similar problem for DELETE tested by delete-12.0.
+# https://sqlite.org/src/info/73f0036f045bf371
+#
+reset_db
+do_execsql_test update-21.1 {
+  CREATE TABLE t1 (vkey INTEGER, c5 INTEGER);
+  INSERT INTO t1 VALUES(3,NULL),(6,-54);
+}
+db null NULL
+do_execsql_test update-21.2 {
+  BEGIN;
+  UPDATE t1 SET vkey = 100 WHERE c5 is null;
+  SELECT * FROM t1 ORDER BY vkey, c5;
+  ROLLBACK;
+} {6 -54 100 NULL}
+do_execsql_test update-21.3 {
+  BEGIN;
+  UPDATE t1 SET vkey = 100 WHERE NOT (-10*(select min(vkey) from t1) >= c5);
+  SELECT * FROM t1 ORDER BY vkey, c5;
+  ROLLBACK;
+} {3 NULL 6 -54}
+do_execsql_test update-21.4 {
+  BEGIN;
+  UPDATE t1 SET vkey = 100 WHERE c5 is null OR NOT (-10*(select min(vkey) from t1) >= c5);
+  SELECT * FROM t1 ORDER BY vkey, c5;
+  ROLLBACK;
+} {6 -54 100 NULL}
+
 finish_test

test/window1.test

@@ -2210,4 +2210,20 @@ do_execsql_test 72.1 {
   SELECT * FROM v1 WHERE true;
 } {1 0}
 
+#-------------------------------------------------------------------------
+reset_db
+
+do_execsql_test 72.0 {
+  CREATE TABLE t0(c0);
+  INSERT INTO t0(c0) VALUES (0);
+  CREATE VIEW v0(c0) AS SELECT TOTAL(0) OVER (PARTITION BY t0.c0) FROM t0;
+}
+do_execsql_test 72.1 {
+  SELECT COUNT(*) FROM (
+      SELECT TOTAL(0) OVER (PARTITION BY t0.c0) FROM t0
+      )
+  WHERE ('1' IS NOT ('abcde' NOTNULL)); 
+} {1}
+
+
 finish_test

tool/mkpragmatab.tcl

@@ -12,7 +12,7 @@
 
 # Flag meanings:
 set flagMeaning(NeedSchema) {Force schema load before running}
-set flagMeaning(ReadOnly)   {Read-only HEADER_VALUE}
+set flagMeaning(OneSchema)  {Only a single schema required}
 set flagMeaning(Result0)    {Acts as query when no argument}
 set flagMeaning(Result1)    {Acts as query when has one argument}
 set flagMeaning(SchemaReq)  {Schema required - "main" is default}
@@ -150,7 +150,7 @@ set pragma_def {
   ARG:  SQLITE_CellSizeCk
 
   NAME: default_cache_size
-  FLAG: NeedSchema Result0 SchemaReq NoColumns1
+  FLAG: NeedSchema Result0 SchemaReq NoColumns1 OneSchema
   COLS: cache_size
   IF:   !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)
 
@@ -163,12 +163,12 @@ set pragma_def {
   IF:   !defined(SQLITE_OMIT_PAGER_PRAGMAS)
 
   NAME: page_count
-  FLAG: NeedSchema Result0 SchemaReq
+  FLAG: NeedSchema Result0 SchemaReq OneSchema
   IF:   !defined(SQLITE_OMIT_PAGER_PRAGMAS)
 
   NAME: max_page_count
   TYPE: PAGE_COUNT
-  FLAG: NeedSchema Result0 SchemaReq
+  FLAG: NeedSchema Result0 SchemaReq OneSchema
   IF:   !defined(SQLITE_OMIT_PAGER_PRAGMAS)
 
   NAME: locking_mode
@@ -176,7 +176,7 @@ set pragma_def {
   IF:   !defined(SQLITE_OMIT_PAGER_PRAGMAS)
 
   NAME: journal_mode
-  FLAG: NeedSchema Result0 SchemaReq
+  FLAG: NeedSchema Result0 SchemaReq OneSchema
   IF:   !defined(SQLITE_OMIT_PAGER_PRAGMAS)
 
   NAME: journal_size_limit
@@ -184,18 +184,18 @@ set pragma_def {
   IF:   !defined(SQLITE_OMIT_PAGER_PRAGMAS)
 
   NAME: cache_size
-  FLAG: NeedSchema Result0 SchemaReq NoColumns1
+  FLAG: NeedSchema Result0 SchemaReq NoColumns1 OneSchema
   IF:   !defined(SQLITE_OMIT_PAGER_PRAGMAS)
 
   NAME: mmap_size
   IF:   !defined(SQLITE_OMIT_PAGER_PRAGMAS)
 
   NAME: auto_vacuum
-  FLAG: NeedSchema Result0 SchemaReq NoColumns1
+  FLAG: NeedSchema Result0 SchemaReq NoColumns1 OneSchema
   IF:   !defined(SQLITE_OMIT_AUTOVACUUM)
 
   NAME: incremental_vacuum
-  FLAG: NeedSchema NoColumns
+  FLAG: NeedSchema NoColumns OneSchema
   IF:   !defined(SQLITE_OMIT_AUTOVACUUM)
 
   NAME: temp_store
@@ -215,7 +215,7 @@ set pragma_def {
   IF:   !defined(SQLITE_OMIT_PAGER_PRAGMAS) && SQLITE_ENABLE_LOCKING_STYLE
 
   NAME: synchronous
-  FLAG: NeedSchema Result0 SchemaReq NoColumns1
+  FLAG: NeedSchema Result0 SchemaReq NoColumns1 OneSchema
   IF:   !defined(SQLITE_OMIT_PAGER_PRAGMAS)
 
   NAME: table_info
@@ -238,7 +238,7 @@ set pragma_def {
   IF:   !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
 
   NAME: stats
-  FLAG: NeedSchema Result0 SchemaReq
+  FLAG: NeedSchema Result0 SchemaReq OneSchema
   COLS: tbl idx wdth hght flgs
   IF:   !defined(SQLITE_OMIT_SCHEMA_PRAGMAS) && defined(SQLITE_DEBUG)
 
@@ -290,7 +290,7 @@ set pragma_def {
   IF:   !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
 
   NAME: foreign_key_list
-  FLAG: NeedSchema Result1 SchemaOpt
+  FLAG: NeedSchema Result1 SchemaOpt OneSchema
   COLS: id seq table from to on_update on_delete match
   IF:   !defined(SQLITE_OMIT_FOREIGN_KEY)
 
@@ -336,14 +336,14 @@ set pragma_def {
 
   NAME: data_version
   TYPE: HEADER_VALUE
-  ARG:  BTREE_DATA_VERSION
-  FLAG: ReadOnly Result0
+  ARG:  BTREE_DATA_VERSION|PRAGMA_HEADER_VALUE_READONLY
+  FLAG: Result0
   IF:   !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
 
   NAME: freelist_count
   TYPE: HEADER_VALUE
-  ARG:  BTREE_FREE_PAGE_COUNT
-  FLAG: ReadOnly Result0
+  ARG:  BTREE_FREE_PAGE_COUNT|PRAGMA_HEADER_VALUE_READONLY
+  FLAG: Result0
   IF:   !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
 
   NAME: application_id
@@ -357,7 +357,7 @@ set pragma_def {
   IF:   !defined(SQLITE_OMIT_COMPILEOPTION_DIAGS)
 
   NAME: wal_checkpoint
-  FLAG: NeedSchema
+  FLAG: NeedSchema OneSchema
   COLS: busy log checkpointed
   IF:   !defined(SQLITE_OMIT_WAL)
 
@@ -516,6 +516,12 @@ foreach f [lsort [array names allflags]] {
   set fv [expr {$fv*2}]
 }
 
+puts $fd "\n/* For PragTyp_HEADER_VALUE pragmas the Pragma.iArg value is set"
+puts $fd "** to the index of the header field to access (always 10 or less)."
+puts $fd "** Ored with HEADER_VALUE_READONLY if the field is read only. */"
+puts $fd "#define PRAGMA_HEADER_VALUE_READONLY 0x0100"
+puts $fd "#define PRAGMA_HEADER_VALUE_MASK 0x00FF\n"
+
 # Sort the column lists so that longer column lists occur first
 #
 proc colscmp {a b} {