Reduce the size of VdbeCursor again, this time without a performance hit.

FossilOrigin-Name: 933939932c44bccb0958f203a5bd24e683c1cf38

ext/fts3/fts3.c

@@ -333,6 +333,9 @@ int sqlite3Fts3PutVarint(char *p, sqlite_int64 v){
 #define GETVARINT_STEP(v, ptr, shift, mask1, mask2, var, ret) \
   v = (v & mask1) | ( (*ptr++) << shift );                    \
   if( (v & mask2)==0 ){ var = v; return ret; }
+#define GETVARINT_INIT(v, ptr, shift, mask1, mask2, var, ret) \
+  v = (*ptr++);                                               \
+  if( (v & mask2)==0 ){ var = v; return ret; }
 
 /* 
 ** Read a 64-bit variable-length integer from memory starting at p[0].
@@ -345,7 +348,7 @@ int sqlite3Fts3GetVarint(const char *p, sqlite_int64 *v){
   u64 b;
   int shift;
 
-  GETVARINT_STEP(a, p, 0,  0x00,     0x80, *v, 1);
+  GETVARINT_INIT(a, p, 0,  0x00,     0x80, *v, 1);
   GETVARINT_STEP(a, p, 7,  0x7F,     0x4000, *v, 2);
   GETVARINT_STEP(a, p, 14, 0x3FFF,   0x200000, *v, 3);
   GETVARINT_STEP(a, p, 21, 0x1FFFFF, 0x10000000, *v, 4);
@@ -357,7 +360,7 @@ int sqlite3Fts3GetVarint(const char *p, sqlite_int64 *v){
     if( (c & 0x80)==0 ) break;
   }
   *v = b;
-  return p - pStart;
+  return (int)(p - pStart);
 }
 
 /*
@@ -368,7 +371,7 @@ int sqlite3Fts3GetVarint32(const char *p, int *pi){
   u32 a;
 
 #ifndef fts3GetVarint32
-  GETVARINT_STEP(a, p, 0,  0x00,     0x80, *pi, 1);
+  GETVARINT_INIT(a, p, 0,  0x00,     0x80, *pi, 1);
 #else
   a = (*p++);
   assert( a & 0x80 );

manifest

@@ -1,5 +1,5 @@
-C Make\ssure\sone-pass\sDELETE\sfor\sWITHOUT\sROWID\stables\scorrectly\spositions\sthe\nPRIMARY\sKEY\scursor.\s\sMake\sthe\ssame\sfix\sfor\sUPDATE.
-D 2013-11-17T02:42:02.540
+C Reduce\sthe\ssize\sof\sVdbeCursor\sagain,\sthis\stime\swithout\sa\sperformance\shit.
+D 2013-11-21T01:04:02.826
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 8a07bebafbfda0eb67728f4bd15a36201662d1a1
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -78,7 +78,7 @@ F ext/fts3/README.content fdc666a70d5257a64fee209f97cf89e0e6e32b51
 F ext/fts3/README.syntax a19711dc5458c20734b8e485e75fb1981ec2427a
 F ext/fts3/README.tokenizers e0a8b81383ea60d0334d274fadf305ea14a8c314
 F ext/fts3/README.txt 8c18f41574404623b76917b9da66fcb0ab38328d
-F ext/fts3/fts3.c dceaa5079833caa2e7945433e1eb93bb22f623a3
+F ext/fts3/fts3.c 1e667eacb3fe4b4ad6f863920da4286f071f6e07
 F ext/fts3/fts3.h 3a10a0af180d502cecc50df77b1b22df142817fe
 F ext/fts3/fts3Int.h eb5f8029589f3d8f1dc7fd50c773326a640388b1
 F ext/fts3/fts3_aux.c 5c211e17a64885faeb16b9ba7772f9d5445c2365
@@ -174,10 +174,10 @@ F src/callback.c f99a8957ba2adf369645fac0db09ad8adcf1caa2
 F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
 F src/ctime.c ea4b7f3623a0fcb1146e7f245d7410033e86859c
 F src/date.c 593c744b2623971e45affd0bde347631bdfa4625
-F src/delete.c d88e4fbfeca5a8cf48b7d358b9a68d5e81f314b7
-F src/expr.c 1a295d8b0a2ba08919ad9300ebf7b67988ff4030
+F src/delete.c 909936019ccb8d0f4a10d0d10ad607c38ee62cbe
+F src/expr.c d81090a3f3bb0845fa6c6795d221ec23ef107737
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
-F src/fkey.c 78364daed38e26269c53ddb94c515bceac1063c6
+F src/fkey.c 2ab0f5384b70594468ef3ac5c7ed8ca24bfd17d5
 F src/func.c 96caa9dfd1febf9a4b720de4c43ccfb392a52b73
 F src/global.c 5caf4deab621abb45b4c607aad1bd21c20aac759
 F src/hash.c ac3470bbf1ca4ae4e306a8ecb0fdf1731810ffe4
@@ -220,8 +220,8 @@ F src/random.c 0b2dbc37fdfbfa6bd455b091dfcef5bdb32dba68
 F src/resolve.c 6fcceeb653a0020b14491975d567c989e794d408
 F src/rowset.c 64655f1a627c9c212d9ab497899e7424a34222e0
 F src/select.c 253cb683e4a05b0b56b0f9c816f3c4a4e5575ebb
-F src/shell.c b98e74123d6c2e20369607c1da2d23c71db633d9
-F src/sqlite.h.in 4dedcab5b32358bf7a596badffe7363be1f1a82d
+F src/shell.c 849ee96c952d20e504d417e42a06acc5ca94ef17
+F src/sqlite.h.in a5dc058a909d9f14470bad9329d9e9303020ea4e
 F src/sqlite3.rc 11094cc6a157a028b301a9f06b3d03089ea37c3e
 F src/sqlite3ext.h 886f5a34de171002ad46fae8c36a7d8051c190fc
 F src/sqliteInt.h 03b91c6bceccd7718473f3d790abcb8d5c2b1bf1
@@ -276,16 +276,16 @@ F src/test_vfstrace.c 34b544e80ba7fb77be15395a609c669df2e660a2
 F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
 F src/tokenize.c ec4c1a62b890bf1dbcdb966399e140b904c700a4
 F src/trigger.c d84e1f3669e9a217731a14a9d472b1c7b87c87ba
-F src/update.c cc3d826923f7b61566dedbb3cfce5f13964f35a4
+F src/update.c c05a0ee658f1a149e0960dfd110f3b8bd846bcb0
 F src/utf.c 6fc6c88d50448c469c5c196acf21617a24f90269
 F src/util.c 2fa6c821d28bbdbeec1b2a7b091a281c9ef8f918
 F src/vacuum.c 3728d74919d4fb1356f9e9a13e27773db60b7179
-F src/vdbe.c 5573893423aec2d64871e8d504fadbcdaad39fed
+F src/vdbe.c c375ba0385f747e58d98686f5f4f0439c6297b35
 F src/vdbe.h c06f0813f853566457ce9cfb1a4a4bc39a5da644
-F src/vdbeInt.h 62eb680327011f3a4b0336642b0ca9d6ecc6eb91
+F src/vdbeInt.h 0ac03c790b8ea4568b747550ba9bbf92a8e8feb2
 F src/vdbeapi.c 93a22a9ba2abe292d5c2cf304d7eb2e894dde0ed
-F src/vdbeaux.c dd0f6ab9dc159911facfc0a7a2164af44779bdda
-F src/vdbeblob.c d883398f7260725147dbf5b40c2b61332aee47f9
+F src/vdbeaux.c bbf06ccbb159611d55e32783c6e9fdec75b120d0
+F src/vdbeblob.c 8cd05a5630e6d5563ad017bf82edaf812b28acde
 F src/vdbemem.c cc529bbf4f13e4e181bdb446bf6e6962ab030b4b
 F src/vdbesort.c 9d83601f9d6243fe70dd0169a2820c5ddfd48147
 F src/vdbetrace.c e7ec40e1999ff3c6414424365d5941178966dcbc
@@ -293,7 +293,7 @@ F src/vtab.c 21b932841e51ebd7d075e2d0ad1415dce8d2d5fd
 F src/wal.c 7dc3966ef98b74422267e7e6e46e07ff6c6eb1b4
 F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4
 F src/walker.c e9e593d5bb798c3e67fc3893dfe7055c9e7d8d74
-F src/where.c de64e326bb2a07e5591900b11a93d743df2a6919
+F src/where.c aa72ba871fa835a513cae1c7432dc1d785eb23e4
 F src/whereInt.h 96a75c61f1d2b9d4a8e4bb17d89deb0cf7cba358
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
@@ -313,7 +313,7 @@ F test/analyze5.test 765c4e284aa69ca172772aa940946f55629bc8c4
 F test/analyze6.test d31defa011a561b938b4608d3538c1b4e0b5e92c
 F test/analyze7.test bb1409afc9e8629e414387ef048b8e0e3e0bdc4f
 F test/analyze8.test 093d15c1c888eed5034304a98c992f7360130b88
-F test/analyze9.test 1b9b7e9a096d1536f03d9ad7b72f638ef5669347
+F test/analyze9.test 339e87723cd4dc158dc5e9095acd8df9e87faf79
 F test/analyzeA.test 1a5c40079894847976d983ca39c707aaa44b6944
 F test/analyzeB.test 8bf35ee0a548aea831bf56762cb8e7fdb1db083d
 F test/async.test 1d0e056ba1bb9729283a0f22718d3a25e82c277b
@@ -437,7 +437,7 @@ F test/e_createtable.test 3b453432cd14a12732ee9467597d2274ca37ce36
 F test/e_delete.test d5186e2f5478b659f16a2c8b66c09892823e542a
 F test/e_droptrigger.test 3cd080807622c13e5bbb61fc9a57bd7754da2412
 F test/e_dropview.test 0c9f7f60989164a70a67a9d9c26d1083bc808306
-F test/e_expr.test d5cdda0e4ffb17760858ed4c7c4ece07efc40f71
+F test/e_expr.test 7d7feeadb555b49476e9ca4a145fcf7c0a81ce34
 F test/e_fkey.test d83a04478bb9c02d2c513518548a69f818869f41
 F test/e_fts3.test 5c02288842e4f941896fd44afdef564dd5fc1459
 F test/e_insert.test 1e44f84d2abe44d66e4fbf198be4b20e3cc724a0
@@ -573,7 +573,7 @@ F test/fts4merge4.test c19c85ca1faa7b6d536832b49c12e1867235f584
 F test/fts4noti.test aed33ba44808852dcb24bf70fa132e7bf530f057
 F test/fts4unicode.test e28ba1a14181e709dcdf47455f207adf14c7cfe0
 F test/full.test 6b3c8fb43c6beab6b95438c1675374b95fab245d
-F test/func.test c7e80a44eebac8604397eb2ad83d0d5d9d541237
+F test/func.test 00667bbeac044d007f6f021af1b9f6150f0c7ff8
 F test/func2.test 772d66227e4e6684b86053302e2d74a2500e1e0f
 F test/func3.test dbccee9133cfef1473c59ec07b5f0262b9d72f9a
 F test/func4.test 6beacdfcb0e18c358e6c2dcacf1b65d1fa80955f
@@ -1140,7 +1140,7 @@ F tool/vdbe-compress.tcl f12c884766bd14277f4fcedcae07078011717381
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh d1a6de74685f360ab718efda6265994b99bbea01
 F tool/win/sqlite.vsix 030f3eeaf2cb811a3692ab9c14d021a75ce41fff
-P a11243f840d35aaed8ee3b9901c3950bc584a417
-R f429117cda51c1a8c08160d9a3f515e6
+P f8d5efcd7b92492b833b6cd1cb6bec006c6a0809
+R 842b8e02c5c12ba51889f25ba6cef74b
 U drh
-Z 2718e457b564d6fbe8d10873d690a300
+Z a21060677c94bf6a3d8120f6bac96f14

manifest.uuid

@@ -1 +1 @@
-6bd5750b7d5da221b0689f6df6be5ed0dce61bec
+933939932c44bccb0958f203a5bd24e683c1cf38

src/delete.c

@@ -244,10 +244,10 @@ void sqlite3DeleteFrom(
   int aiCurOnePass[2];   /* The write cursors opened by WHERE_ONEPASS */
   u8 *aToOpen = 0;       /* Open cursor iTabCur+j if aToOpen[j] is true */
   Index *pPk;            /* The PRIMARY KEY index on the table */
-  int iPk;               /* First of nPk registerss holding PRIMARY KEY value */
-  i16 nPk = 1;           /* Number of components of the PRIMARY KEY */
-  int iKey;              /* Memory cell holding row key of to be deleted */
-  i16 nKey;              /* Number of memory cells of row key */
+  int iPk;               /* First of nPk registers holding PRIMARY KEY value */
+  i16 nPk = 1;           /* Number of columns in the PRIMARY KEY */
+  int iKey;              /* Memory cell holding key of row to be deleted */
+  i16 nKey;              /* Number of memory cells in the row key */
   int iEphCur = 0;       /* Ephemeral table holding all primary key values */
   int iRowSet = 0;       /* Register for rowset of rows to delete */
   int addrBypass = 0;    /* Address of jump over the delete logic */
@@ -420,7 +420,6 @@ void sqlite3DeleteFrom(
                                         pPk->aiColumn[i], iPk+i);
       }
       iKey = iPk;
-      nKey = nPk;
     }else{
       iKey = pParse->nMem + 1;
       iKey = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iTabCur, iKey, 0);

src/expr.c

@@ -1193,7 +1193,7 @@ static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
     /* Consider functions to be constant if all their arguments are constant
     ** and pWalker->u.i==2 */
     case TK_FUNCTION:
-      if( pWalker->u.i==2 ) return 0;
+      if( pWalker->u.i==2 ) return WRC_Continue;
       /* Fall through */
     case TK_ID:
     case TK_COLUMN:

src/fkey.c

@@ -548,6 +548,7 @@ static void fkScanChildren(
   assert( pIdx==0 || pIdx->pTable==pTab );
   assert( pIdx==0 || pIdx->nKeyCol==pFKey->nCol );
   assert( pIdx!=0 || pFKey->nCol==1 );
+  assert( pIdx!=0 || HasRowid(pTab) );
 
   if( nIncr<0 ){
     iFkIfZero = sqlite3VdbeAddOp2(v, OP_FkIfZero, pFKey->isDeferred, 0);
@@ -600,6 +601,7 @@ static void fkScanChildren(
     }else{
       Expr *pEq, *pAll = 0;
       Index *pPk = sqlite3PrimaryKeyIndex(pTab);
+      assert( pIdx!=0 );
       for(i=0; i<pPk->nKeyCol; i++){
         i16 iCol = pIdx->aiColumn[i];
         pLeft = exprTableRegister(pParse, pTab, regData, iCol);

src/shell.c

@@ -466,6 +466,7 @@ struct callback_data {
   FILE *pLog;            /* Write log output here */
   int *aiIndent;         /* Array of indents used in MODE_Explain */
   int nIndent;           /* Size of array aiIndent[] */
+  int iIndent;           /* Index of current op in aiIndent[] */
 };
 
 /*
@@ -771,10 +772,10 @@ static int shell_callback(void *pArg, int nArg, char **azArg, char **azCol, int
           w = strlen30(azArg[i]);
         }
         if( i==1 && p->aiIndent && p->pStmt ){
-          int iOp = sqlite3_column_int(p->pStmt, 0);
-          if( iOp<p->nIndent ){
-            fprintf(p->out, "%*.s", p->aiIndent[iOp], "");
+          if( p->iIndent<p->nIndent ){
+            fprintf(p->out, "%*.s", p->aiIndent[p->iIndent], "");
           }
+          p->iIndent++;
         }
         if( w<0 ){
           fprintf(p->out,"%*.*s%s",-w,-w,
@@ -1184,7 +1185,7 @@ static void explain_data_prepare(struct callback_data *p, sqlite3_stmt *pSql){
   const char *z;                  /* Used to check if this is an EXPLAIN */
   int *abYield = 0;               /* True if op is an OP_Yield */
   int nAlloc = 0;                 /* Allocated size of p->aiIndent[], abYield */
-  int iOp;
+  int iOp;                        /* Index of operation in p->aiIndent[] */
 
   const char *azNext[] = { "Next", "Prev", "VPrev", "VNext", "SorterNext", 0 };
   const char *azYield[] = { "Yield", "SeekLt", "SeekGt", "RowSetRead", 0 };
@@ -1199,8 +1200,16 @@ static void explain_data_prepare(struct callback_data *p, sqlite3_stmt *pSql){
 
   for(iOp=0; SQLITE_ROW==sqlite3_step(pSql); iOp++){
     int i;
+    int iAddr = sqlite3_column_int(pSql, 0);
     const char *zOp = (const char*)sqlite3_column_text(pSql, 1);
+
+    /* Set p2 to the P2 field of the current opcode. Then, assuming that
+    ** p2 is an instruction address, set variable p2op to the index of that
+    ** instruction in the aiIndent[] array. p2 and p2op may be different if
+    ** the current instruction is part of a sub-program generated by an
+    ** SQL trigger or foreign key.  */
     int p2 = sqlite3_column_int(pSql, 3);
+    int p2op = (p2 + (iOp-iAddr));
 
     /* Grow the p->aiIndent array as required */
     if( iOp>=nAlloc ){
@@ -1213,13 +1222,14 @@ static void explain_data_prepare(struct callback_data *p, sqlite3_stmt *pSql){
     p->nIndent = iOp+1;
 
     if( str_in_array(zOp, azNext) ){
-      for(i=p2; i<iOp; i++) p->aiIndent[i] += 2;
+      for(i=p2op; i<iOp; i++) p->aiIndent[i] += 2;
     }
-    if( str_in_array(zOp, azGoto) && p2<p->nIndent && abYield[p2] ){
-      for(i=p2+1; i<iOp; i++) p->aiIndent[i] += 2;
+    if( str_in_array(zOp, azGoto) && p2op<p->nIndent && abYield[p2op] ){
+      for(i=p2op; i<iOp; i++) p->aiIndent[i] += 2;
     }
   }
 
+  p->iIndent = 0;
   sqlite3_free(abYield);
   sqlite3_reset(pSql);
 }
@@ -1231,6 +1241,7 @@ static void explain_data_delete(struct callback_data *p){
   sqlite3_free(p->aiIndent);
   p->aiIndent = 0;
   p->nIndent = 0;
+  p->iIndent = 0;
 }
 
 /*

src/sqlite.h.in

@@ -365,7 +365,7 @@ typedef int (*sqlite3_callback)(void*,int,char**, char**);
 ** <ul>
 ** <li> The application must insure that the 1st parameter to sqlite3_exec()
 **      is a valid and open [database connection].
-** <li> The application must not close [database connection] specified by
+** <li> The application must not close the [database connection] specified by
 **      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
 ** <li> The application must not modify the SQL statement text passed into
 **      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
@@ -442,7 +442,7 @@ int sqlite3_exec(
 ** [sqlite3_extended_result_codes()] API.
 **
 ** Some of the available extended result codes are listed here.
-** One may expect the number of extended result codes will be expand
+** One may expect the number of extended result codes will increase
 ** over time.  Software that uses extended result codes should expect
 ** to see new result codes in future releases of SQLite.
 **
@@ -1380,7 +1380,7 @@ int sqlite3_db_config(sqlite3*, int op, ...);
 ** or [sqlite3_realloc()] first calls xRoundup.  If xRoundup returns 0, 
 ** that causes the corresponding memory allocation to fail.
 **
-** The xInit method initializes the memory allocator.  (For example,
+** The xInit method initializes the memory allocator.  For example,
 ** it might allocate any require mutexes or initialize internal data
 ** structures.  The xShutdown method is invoked (indirectly) by
 ** [sqlite3_shutdown()] and should deallocate any resources acquired
@@ -3106,7 +3106,6 @@ int sqlite3_limit(sqlite3*, int id, int newVal);
 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
 ** or [GLOB] operator or if the parameter is compared to an indexed column
 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
-** the 
 ** </li>
 ** </ol>
 */
@@ -3836,7 +3835,7 @@ int sqlite3_data_count(sqlite3_stmt *pStmt);
 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
 ** [sqlite3_finalize()] is called.  ^The memory space used to hold strings
 ** and BLOBs is freed automatically.  Do <b>not</b> pass the pointers returned
-** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
+** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
 ** [sqlite3_free()].
 **
 ** ^(If a memory allocation error occurs during the evaluation of any
@@ -4914,8 +4913,8 @@ int sqlite3_release_memory(int);
 **
 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
 ** memory as possible from database connection D. Unlike the
-** [sqlite3_release_memory()] interface, this interface is effect even
-** when then [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
+** [sqlite3_release_memory()] interface, this interface is in effect even
+** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
 ** omitted.
 **
 ** See also: [sqlite3_release_memory()]

src/update.c

@@ -263,6 +263,11 @@ void sqlite3Update(
   assert( chngPk==0 || chngPk==1 );
   chngKey = chngRowid + chngPk;
 
+  /* The SET expressions are not actually used inside the WHERE loop.
+  ** So reset the colUsed mask
+  */
+  pTabList->a[0].colUsed = 0;
+
   hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey);
 
   /* There is one entry in the aRegIdx[] array for each index on the table

src/vdbe.c

@@ -212,9 +212,8 @@ static VdbeCursor *allocateCursor(
   int nByte;
   VdbeCursor *pCx = 0;
   nByte = 
-      ROUND8(sizeof(VdbeCursor)) + 
-      (isBtreeCursor?sqlite3BtreeCursorSize():0) + 
-      2*nField*sizeof(u32);
+      ROUND8(sizeof(VdbeCursor)) + 2*sizeof(u32)*nField + 
+      (isBtreeCursor?sqlite3BtreeCursorSize():0);
 
   assert( iCur<p->nCursor );
   if( p->apCsr[iCur] ){
@@ -226,12 +225,9 @@ static VdbeCursor *allocateCursor(
     memset(pCx, 0, sizeof(VdbeCursor));
     pCx->iDb = iDb;
     pCx->nField = nField;
-    if( nField ){
-      pCx->aType = (u32 *)&pMem->z[ROUND8(sizeof(VdbeCursor))];
-    }
     if( isBtreeCursor ){
       pCx->pCursor = (BtCursor*)
-          &pMem->z[ROUND8(sizeof(VdbeCursor))+2*nField*sizeof(u32)];
+          &pMem->z[ROUND8(sizeof(VdbeCursor))+2*sizeof(u32)*nField];
       sqlite3BtreeCursorZero(pCx->pCursor);
     }
   }
@@ -1662,17 +1658,19 @@ case OP_AddImm: {            /* in1 */
 */
 case OP_MustBeInt: {            /* jump, in1 */
   pIn1 = &aMem[pOp->p1];
-  applyAffinity(pIn1, SQLITE_AFF_NUMERIC, encoding);
   if( (pIn1->flags & MEM_Int)==0 ){
-    if( pOp->p2==0 ){
-      rc = SQLITE_MISMATCH;
-      goto abort_due_to_error;
-    }else{
-      pc = pOp->p2 - 1;
+    applyAffinity(pIn1, SQLITE_AFF_NUMERIC, encoding);
+    if( (pIn1->flags & MEM_Int)==0 ){
+      if( pOp->p2==0 ){
+        rc = SQLITE_MISMATCH;
+        goto abort_due_to_error;
+      }else{
+        pc = pOp->p2 - 1;
+        break;
+      }
     }
-  }else{
-    MemSetTypeFlag(pIn1, MEM_Int);
   }
+  MemSetTypeFlag(pIn1, MEM_Int);
   break;
 }
 
@@ -2251,151 +2249,103 @@ case OP_NotNull: {            /* same as TK_NOTNULL, jump, in1 */
 ** skipped for length() and all content loading can be skipped for typeof().
 */
 case OP_Column: {
-  u32 payloadSize;   /* Number of bytes in the record */
   i64 payloadSize64; /* Number of bytes in the record */
-  int p1;            /* P1 value of the opcode */
   int p2;            /* column number to retrieve */
   VdbeCursor *pC;    /* The VDBE cursor */
-  char *zRec;        /* Pointer to complete record-data */
   BtCursor *pCrsr;   /* The BTree cursor */
   u32 *aType;        /* aType[i] holds the numeric type of the i-th column */
   u32 *aOffset;      /* aOffset[i] is offset to start of data for i-th column */
-  int nField;        /* number of fields in the record */
   int len;           /* The length of the serialized data for the column */
   int i;             /* Loop counter */
-  char *zData;       /* Part of the record being decoded */
   Mem *pDest;        /* Where to write the extracted value */
   Mem sMem;          /* For storing the record being decoded */
-  u8 *zIdx;          /* Index into header */
-  u8 *zEndHdr;       /* Pointer to first byte after the header */
+  const u8 *zData;   /* Part of the record being decoded */
+  const u8 *zHdr;    /* Next unparsed byte of the header */
+  const u8 *zEndHdr; /* Pointer to first byte after the header */
   u32 offset;        /* Offset into the data */
   u32 szField;       /* Number of bytes in the content of a field */
-  int szHdr;         /* Size of the header size field at start of record */
   int avail;         /* Number of bytes of available data */
   u32 t;             /* A type code from the record header */
   Mem *pReg;         /* PseudoTable input register */
 
-
-  p1 = pOp->p1;
   p2 = pOp->p2;
-  pC = 0;
-  memset(&sMem, 0, sizeof(sMem));
-  assert( p1<p->nCursor );
   assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
   pDest = &aMem[pOp->p3];
   memAboutToChange(p, pDest);
-  zRec = 0;
-
-  /* This block sets the variable payloadSize to be the total number of
-  ** bytes in the record.
-  **
-  ** zRec is set to be the complete text of the record if it is available.
-  ** The complete record text is always available for pseudo-tables
-  ** If the record is stored in a cursor, the complete record text
-  ** might be available in the  pC->aRow cache.  Or it might not be.
-  ** If the data is unavailable,  zRec is set to NULL.
-  **
-  ** We also compute the number of columns in the record.  For cursors,
-  ** the number of columns is stored in the VdbeCursor.nField element.
-  */
-  pC = p->apCsr[p1];
+  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
+  pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
+  assert( p2<pC->nField );
+  aType = pC->aType;
+  aOffset = aType + pC->nField;
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-  assert( pC->pVtabCursor==0 );
+  assert( pC->pVtabCursor==0 ); /* OP_Column never called on virtual table */
 #endif
   pCrsr = pC->pCursor;
-  if( pCrsr!=0 ){
-    /* The record is stored in a B-Tree */
-    rc = sqlite3VdbeCursorMoveto(pC);
-    if( rc ) goto abort_due_to_error;
+  assert( pCrsr!=0 || pC->pseudoTableReg>0 ); /* pCrsr NULL on PseudoTables */
+  assert( pCrsr!=0 || pC->nullRow );          /* pC->nullRow on PseudoTables */
+
+  /* If the cursor cache is stale, bring it up-to-date */
+  rc = sqlite3VdbeCursorMoveto(pC);
+  if( rc ) goto abort_due_to_error;
+  if( pC->cacheStatus!=p->cacheCtr || (pOp->p5&OPFLAG_CLEARCACHE)!=0 ){
     if( pC->nullRow ){
-      payloadSize = 0;
-    }else if( pC->cacheStatus==p->cacheCtr ){
-      payloadSize = pC->payloadSize;
-      zRec = (char*)pC->aRow;
-    }else if( pC->isIndex ){
-      assert( sqlite3BtreeCursorIsValid(pCrsr) );
-      VVA_ONLY(rc =) sqlite3BtreeKeySize(pCrsr, &payloadSize64);
-      assert( rc==SQLITE_OK );   /* True because of CursorMoveto() call above */
-      /* sqlite3BtreeParseCellPtr() uses getVarint32() to extract the
-      ** payload size, so it is impossible for payloadSize64 to be
-      ** larger than 32 bits. */
-      assert( (payloadSize64 & SQLITE_MAX_U32)==(u64)payloadSize64 );
-      payloadSize = (u32)payloadSize64;
+      if( pCrsr==0 ){
+        assert( pC->pseudoTableReg>0 );
+        pReg = &aMem[pC->pseudoTableReg];
+        if( pC->multiPseudo ){
+          sqlite3VdbeMemShallowCopy(pDest, pReg+p2, MEM_Ephem);
+          Deephemeralize(pDest);
+          goto op_column_out;
+        }
+        assert( pReg->flags & MEM_Blob );
+        assert( memIsValid(pReg) );
+        pC->payloadSize = pC->szRow = avail = pReg->n;
+        pC->aRow = (u8*)pReg->z;
+      }else{
+        MemSetTypeFlag(pDest, MEM_Null);
+        goto op_column_out;
+      }
     }else{
-      assert( sqlite3BtreeCursorIsValid(pCrsr) );
-      VVA_ONLY(rc =) sqlite3BtreeDataSize(pCrsr, &payloadSize);
-      assert( rc==SQLITE_OK );   /* DataSize() cannot fail */
+      assert( pCrsr );
+      if( pC->isTable==0 ){
+        assert( sqlite3BtreeCursorIsValid(pCrsr) );
+        VVA_ONLY(rc =) sqlite3BtreeKeySize(pCrsr, &payloadSize64);
+        assert( rc==SQLITE_OK ); /* True because of CursorMoveto() call above */
+        /* sqlite3BtreeParseCellPtr() uses getVarint32() to extract the
+        ** payload size, so it is impossible for payloadSize64 to be
+        ** larger than 32 bits. */
+        assert( (payloadSize64 & SQLITE_MAX_U32)==(u64)payloadSize64 );
+        pC->aRow = sqlite3BtreeKeyFetch(pCrsr, &avail);
+        pC->payloadSize = (u32)payloadSize64;
+      }else{
+        assert( sqlite3BtreeCursorIsValid(pCrsr) );
+        VVA_ONLY(rc =) sqlite3BtreeDataSize(pCrsr, &pC->payloadSize);
+        assert( rc==SQLITE_OK );   /* DataSize() cannot fail */
+        pC->aRow = sqlite3BtreeDataFetch(pCrsr, &avail);
+      }
+      assert( avail<=65536 );  /* Maximum page size is 64KiB */
+      if( pC->payloadSize <= (u32)avail ){
+        pC->szRow = pC->payloadSize;
+      }else{
+        pC->szRow = avail;
+      }
+      if( pC->payloadSize > (u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
+        goto too_big;
+      }
     }
-  }else{
-    assert( pC->pseudoTableReg>0 );
-    pReg = &aMem[pC->pseudoTableReg];
-    if( pC->multiPseudo ){
-      sqlite3VdbeMemShallowCopy(pDest, pReg+p2, MEM_Ephem);
-      Deephemeralize(pDest);
-      goto op_column_out;
-    }
-    assert( pReg->flags & MEM_Blob );
-    assert( memIsValid(pReg) );
-    payloadSize = pReg->n;
-    zRec = pReg->z;
-    pC->cacheStatus = (pOp->p5&OPFLAG_CLEARCACHE) ? CACHE_STALE : p->cacheCtr;
-    assert( payloadSize==0 || zRec!=0 );
-  }
-
-  /* If payloadSize is 0, then just store a NULL.  This can happen because of
-  ** nullRow or because of a corrupt database. */
-  if( payloadSize==0 ){
-    MemSetTypeFlag(pDest, MEM_Null);
-    goto op_column_out;
-  }
-  assert( db->aLimit[SQLITE_LIMIT_LENGTH]>=0 );
-  if( payloadSize > (u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
-    goto too_big;
-  }
-
-  nField = pC->nField;
-  assert( p2<nField );
-
-  /* Read and parse the table header.  Store the results of the parse
-  ** into the record header cache fields of the cursor.
-  */
-  aType = pC->aType;
-  if( pC->cacheStatus==p->cacheCtr ){
-    aOffset = pC->aOffset;
-  }else{
-    assert(aType);
-    avail = 0;
-    pC->aOffset = aOffset = &aType[nField];
-    pC->payloadSize = payloadSize;
     pC->cacheStatus = p->cacheCtr;
-
-    /* Figure out how many bytes are in the header */
-    if( zRec ){
-      zData = zRec;
-    }else{
-      if( pC->isIndex ){
-        zData = (char*)sqlite3BtreeKeyFetch(pCrsr, &avail);
-      }else{
-        zData = (char*)sqlite3BtreeDataFetch(pCrsr, &avail);
-      }
-      /* If KeyFetch()/DataFetch() managed to get the entire payload,
-      ** save the payload in the pC->aRow cache.  That will save us from
-      ** having to make additional calls to fetch the content portion of
-      ** the record.
-      */
-      assert( avail>=0 );
-      if( payloadSize <= (u32)avail ){
-        zRec = zData;
-        pC->aRow = (u8*)zData;
-      }else{
-        pC->aRow = 0;
-      }
+    pC->iHdrOffset = getVarint32(pC->aRow, offset);
+    pC->nHdrParsed = 0;
+    aOffset[0] = offset;
+    if( avail<offset ){
+      /* pC->aRow does not have to hold the entire row, but it does at least
+      ** need to cover the header of the record.  If pC->aRow does not contain
+      ** the complete header, then set it to zero, forcing the header to be
+      ** dynamically allocated. */
+      pC->aRow = 0;
+      pC->szRow = 0;
     }
-    /* The following assert is true in all cases except when
-    ** the database file has been corrupted externally.
-    **    assert( zRec!=0 || avail>=payloadSize || avail>=9 ); */
-    szHdr = getVarint32((u8*)zData, offset);
 
     /* Make sure a corrupt database has not given us an oversize header.
     ** Do this now to avoid an oversize memory allocation.
@@ -2406,155 +2356,148 @@ case OP_Column: {
     ** 3-byte type for each of the maximum of 32768 columns plus three
     ** extra bytes for the header length itself.  32768*3 + 3 = 98307.
     */
-    if( offset > 98307 ){
+    if( offset > 98307 || offset > pC->payloadSize ){
       rc = SQLITE_CORRUPT_BKPT;
-      goto op_column_out;
+      goto op_column_error;
     }
+  }
 
-    /* Compute in len the number of bytes of data we need to read in order
-    ** to get nField type values.  offset is an upper bound on this.  But
-    ** nField might be significantly less than the true number of columns
-    ** in the table, and in that case, 5*nField+3 might be smaller than offset.
-    ** We want to minimize len in order to limit the size of the memory
-    ** allocation, especially if a corrupt database file has caused offset
-    ** to be oversized. Offset is limited to 98307 above.  But 98307 might
-    ** still exceed Robson memory allocation limits on some configurations.
-    ** On systems that cannot tolerate large memory allocations, nField*5+3
-    ** will likely be much smaller since nField will likely be less than
-    ** 20 or so.  This insures that Robson memory allocation limits are
-    ** not exceeded even for corrupt database files.
+  /* Make sure at least the first p2+1 entries of the header have been
+  ** parsed and valid information is in aOffset[] and aType[].
+  */
+  if( pC->nHdrParsed<=p2 ){
+    /* If there is more header available for parsing in the record, try
+    ** to extract additional fields up through the p2+1-th field 
     */
-    len = nField*5 + 3;
-    if( len > (int)offset ) len = (int)offset;
-
-    /* The KeyFetch() or DataFetch() above are fast and will get the entire
-    ** record header in most cases.  But they will fail to get the complete
-    ** record header if the record header does not fit on a single page
-    ** in the B-Tree.  When that happens, use sqlite3VdbeMemFromBtree() to
-    ** acquire the complete header text.
-    */
-    if( !zRec && avail<len ){
-      sMem.flags = 0;
-      sMem.db = 0;
-      rc = sqlite3VdbeMemFromBtree(pCrsr, 0, len, pC->isIndex, &sMem);
-      if( rc!=SQLITE_OK ){
-        goto op_column_out;
+    if( pC->iHdrOffset<aOffset[0] ){
+      /* Make sure zData points to enough of the record to cover the header. */
+      if( pC->aRow==0 ){
+        memset(&sMem, 0, sizeof(sMem));
+        rc = sqlite3VdbeMemFromBtree(pCrsr, 0, aOffset[0], 
+                                     !pC->isTable, &sMem);
+        if( rc!=SQLITE_OK ){
+          goto op_column_error;
+        }
+        zData = (u8*)sMem.z;
+      }else{
+        zData = pC->aRow;
       }
-      zData = sMem.z;
-    }
-    zEndHdr = (u8 *)&zData[len];
-    zIdx = (u8 *)&zData[szHdr];
-
-    /* Scan the header and use it to fill in the aType[] and aOffset[]
-    ** arrays.  aType[i] will contain the type integer for the i-th
-    ** column and aOffset[i] will contain the offset from the beginning
-    ** of the record to the start of the data for the i-th column
-    */
-    for(i=0; i<nField; i++){
-      if( zIdx<zEndHdr ){
-        aOffset[i] = offset;
-        if( zIdx[0]<0x80 ){
-          t = zIdx[0];
-          zIdx++;
+  
+      /* Fill in aType[i] and aOffset[i] values through the p2-th field. */
+      i = pC->nHdrParsed;
+      offset = aOffset[i];
+      zHdr = zData + pC->iHdrOffset;
+      zEndHdr = zData + aOffset[0];
+      assert( i<=p2 && zHdr<zEndHdr );
+      do{
+        if( zHdr[0]<0x80 ){
+          t = zHdr[0];
+          zHdr++;
         }else{
-          zIdx += sqlite3GetVarint32(zIdx, &t);
+          zHdr += sqlite3GetVarint32(zHdr, &t);
         }
         aType[i] = t;
         szField = sqlite3VdbeSerialTypeLen(t);
         offset += szField;
         if( offset<szField ){  /* True if offset overflows */
-          zIdx = &zEndHdr[1];  /* Forces SQLITE_CORRUPT return below */
+          zHdr = &zEndHdr[1];  /* Forces SQLITE_CORRUPT return below */
           break;
         }
-      }else{
-        /* If i is less that nField, then there are fewer fields in this
-        ** record than SetNumColumns indicated there are columns in the
-        ** table. Set the offset for any extra columns not present in
-        ** the record to 0. This tells code below to store the default value
-        ** for the column instead of deserializing a value from the record.
-        */
-        aOffset[i] = 0;
+        i++;
+        aOffset[i] = offset;
+      }while( i<=p2 && zHdr<zEndHdr );
+      pC->nHdrParsed = i;
+      pC->iHdrOffset = (u32)(zHdr - zData);
+      if( pC->aRow==0 ){
+        sqlite3VdbeMemRelease(&sMem);
+        sMem.flags = MEM_Null;
+      }
+  
+      /* If we have read more header data than was contained in the header,
+      ** or if the end of the last field appears to be past the end of the
+      ** record, or if the end of the last field appears to be before the end
+      ** of the record (when all fields present), then we must be dealing 
+      ** with a corrupt database.
+      */
+      if( (zHdr > zEndHdr)
+       || (offset > pC->payloadSize)
+       || (zHdr==zEndHdr && offset!=pC->payloadSize)
+      ){
+        rc = SQLITE_CORRUPT_BKPT;
+        goto op_column_error;
       }
     }
-    sqlite3VdbeMemRelease(&sMem);
-    sMem.flags = MEM_Null;
 
-    /* If we have read more header data than was contained in the header,
-    ** or if the end of the last field appears to be past the end of the
-    ** record, or if the end of the last field appears to be before the end
-    ** of the record (when all fields present), then we must be dealing 
-    ** with a corrupt database.
+    /* If after trying to extra new entries from the header, nHdrParsed is
+    ** still not up to p2, that means that the record has fewer than p2
+    ** columns.  So the result will be either the default value or a NULL.
     */
-    if( (zIdx > zEndHdr) || (offset > payloadSize)
-         || (zIdx==zEndHdr && offset!=payloadSize) ){
-      rc = SQLITE_CORRUPT_BKPT;
+    if( pC->nHdrParsed<=p2 ){
+      if( pOp->p4type==P4_MEM ){
+        sqlite3VdbeMemShallowCopy(pDest, pOp->p4.pMem, MEM_Static);
+      }else{
+        MemSetTypeFlag(pDest, MEM_Null);
+      }
       goto op_column_out;
     }
   }
 
-  /* Get the column information. If aOffset[p2] is non-zero, then 
-  ** deserialize the value from the record. If aOffset[p2] is zero,
-  ** then there are not enough fields in the record to satisfy the
-  ** request.  In this case, set the value NULL or to P4 if P4 is
-  ** a pointer to a Mem object.
+  /* Extract the content for the p2+1-th column.  Control can only
+  ** reach this point if aOffset[p2], aOffset[p2+1], and aType[p2] are
+  ** all valid.
   */
-  if( aOffset[p2] ){
-    assert( rc==SQLITE_OK );
-    if( zRec ){
-      /* This is the common case where the whole row fits on a single page */
-      VdbeMemRelease(pDest);
-      sqlite3VdbeSerialGet((u8 *)&zRec[aOffset[p2]], aType[p2], pDest);
-    }else{
-      /* This branch happens only when the row overflows onto multiple pages */
-      t = aType[p2];
-      if( (pOp->p5 & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG))!=0
-       && ((t>=12 && (t&1)==0) || (pOp->p5 & OPFLAG_TYPEOFARG)!=0)
-      ){
-        /* Content is irrelevant for the typeof() function and for
-        ** the length(X) function if X is a blob.  So we might as well use
-        ** bogus content rather than reading content from disk.  NULL works
-        ** for text and blob and whatever is in the payloadSize64 variable
-        ** will work for everything else. */
-        zData = t<12 ? (char*)&payloadSize64 : 0;
-      }else{
-        len = sqlite3VdbeSerialTypeLen(t);
-        sqlite3VdbeMemMove(&sMem, pDest);
-        rc = sqlite3VdbeMemFromBtree(pCrsr, aOffset[p2], len,  pC->isIndex,
-                                     &sMem);
-        if( rc!=SQLITE_OK ){
-          goto op_column_out;
-        }
-        zData = sMem.z;
-      }
-      sqlite3VdbeSerialGet((u8*)zData, t, pDest);
-    }
-    pDest->enc = encoding;
+  assert( p2<pC->nHdrParsed );
+  assert( rc==SQLITE_OK );
+  if( pC->szRow>=aOffset[p2+1] ){
+    /* This is the common case where the desired content fits on the original
+    ** page - where the content is not on an overflow page */
+    VdbeMemRelease(pDest);
+    sqlite3VdbeSerialGet(pC->aRow+aOffset[p2], aType[p2], pDest);
   }else{
-    if( pOp->p4type==P4_MEM ){
-      sqlite3VdbeMemShallowCopy(pDest, pOp->p4.pMem, MEM_Static);
+    /* This branch happens only when content is on overflow pages */	
+    t = aType[p2];
+    if( ((pOp->p5 & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG))!=0
+          && ((t>=12 && (t&1)==0) || (pOp->p5 & OPFLAG_TYPEOFARG)!=0))
+     || (len = sqlite3VdbeSerialTypeLen(t))==0
+    ){
+      /* Content is irrelevant for the typeof() function and for
+      ** the length(X) function if X is a blob.  So we might as well use
+      ** bogus content rather than reading content from disk.  NULL works
+      ** for text and blob and whatever is in the payloadSize64 variable
+      ** will work for everything else.  Content is also irrelevant if
+      ** the content length is 0. */
+      zData = t<=13 ? (u8*)&payloadSize64 : 0;
+      sMem.zMalloc = 0;
     }else{
-      MemSetTypeFlag(pDest, MEM_Null);
+      memset(&sMem, 0, sizeof(sMem));
+      sqlite3VdbeMemMove(&sMem, pDest);
+      rc = sqlite3VdbeMemFromBtree(pCrsr, aOffset[p2], len, !pC->isTable,
+                                   &sMem);
+      if( rc!=SQLITE_OK ){
+        goto op_column_error;
+      }
+      zData = (u8*)sMem.z;
+    }
+    sqlite3VdbeSerialGet(zData, t, pDest);
+    /* If we dynamically allocated space to hold the data (in the
+    ** sqlite3VdbeMemFromBtree() call above) then transfer control of that
+    ** dynamically allocated space over to the pDest structure.
+    ** This prevents a memory copy. */
+    if( sMem.zMalloc ){
+      assert( sMem.z==sMem.zMalloc );
+      assert( !(pDest->flags & MEM_Dyn) );
+      assert( !(pDest->flags & (MEM_Blob|MEM_Str)) || pDest->z==sMem.z );
+      pDest->flags &= ~(MEM_Ephem|MEM_Static);
+      pDest->flags |= MEM_Term;
+      pDest->z = sMem.z;
+      pDest->zMalloc = sMem.zMalloc;
     }
   }
-
-  /* If we dynamically allocated space to hold the data (in the
-  ** sqlite3VdbeMemFromBtree() call above) then transfer control of that
-  ** dynamically allocated space over to the pDest structure.
-  ** This prevents a memory copy.
-  */
-  if( sMem.zMalloc ){
-    assert( sMem.z==sMem.zMalloc );
-    assert( !(pDest->flags & MEM_Dyn) );
-    assert( !(pDest->flags & (MEM_Blob|MEM_Str)) || pDest->z==sMem.z );
-    pDest->flags &= ~(MEM_Ephem|MEM_Static);
-    pDest->flags |= MEM_Term;
-    pDest->z = sMem.z;
-    pDest->zMalloc = sMem.zMalloc;
-  }
-
-  rc = sqlite3VdbeMemMakeWriteable(pDest);
+  pDest->enc = encoding;
 
 op_column_out:
+  rc = sqlite3VdbeMemMakeWriteable(pDest);
+op_column_error:
   UPDATE_MAX_BLOBSIZE(pDest);
   REGISTER_TRACE(pOp->p3, pDest);
   break;
@@ -3310,6 +3253,8 @@ case OP_OpenWrite: {
     nField = pOp->p4.i;
   }
   assert( pOp->p1>=0 );
+  assert( nField>=0 );
+  testcase( nField==0 );  /* Table with INTEGER PRIMARY KEY and nothing else */
   pCur = allocateCursor(p, pOp->p1, nField, iDb, 1);
   if( pCur==0 ) goto no_mem;
   pCur->nullRow = 1;
@@ -3323,12 +3268,11 @@ case OP_OpenWrite: {
   ** sqlite3BtreeCursor() may return is SQLITE_OK. */
   assert( rc==SQLITE_OK );
 
-  /* Set the VdbeCursor.isTable and isIndex variables. Previous versions of
+  /* Set the VdbeCursor.isTable variable. Previous versions of
   ** SQLite used to check if the root-page flags were sane at this point
   ** and report database corruption if they were not, but this check has
   ** since moved into the btree layer.  */  
   pCur->isTable = pOp->p4type!=P4_KEYINFO;
-  pCur->isIndex = !pCur->isTable;
   break;
 }
 
@@ -3370,6 +3314,7 @@ case OP_OpenEphemeral: {
       SQLITE_OPEN_DELETEONCLOSE |
       SQLITE_OPEN_TRANSIENT_DB;
   assert( pOp->p1>=0 );
+  assert( pOp->p2>=0 );
   pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, 1);
   if( pCx==0 ) goto no_mem;
   pCx->nullRow = 1;
@@ -3402,7 +3347,6 @@ case OP_OpenEphemeral: {
     }
   }
   pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
-  pCx->isIndex = !pCx->isTable;
   break;
 }
 
@@ -3415,12 +3359,13 @@ case OP_OpenEphemeral: {
 case OP_SorterOpen: {
   VdbeCursor *pCx;
 
+  assert( pOp->p1>=0 );
+  assert( pOp->p2>=0 );
   pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, 1);
   if( pCx==0 ) goto no_mem;
   pCx->pKeyInfo = pOp->p4.pKeyInfo;
   assert( pCx->pKeyInfo->db==db );
   assert( pCx->pKeyInfo->enc==ENC(db) );
-  pCx->isSorter = 1;
   rc = sqlite3VdbeSorterInit(db, pCx);
   break;
 }
@@ -3446,12 +3391,12 @@ case OP_OpenPseudo: {
   VdbeCursor *pCx;
 
   assert( pOp->p1>=0 );
+  assert( pOp->p3>=0 );
   pCx = allocateCursor(p, pOp->p1, pOp->p3, -1, 0);
   if( pCx==0 ) goto no_mem;
   pCx->nullRow = 1;
   pCx->pseudoTableReg = pOp->p2;
   pCx->isTable = 1;
-  pCx->isIndex = 0;
   pCx->multiPseudo = pOp->p5;
   break;
 }
@@ -4267,7 +4212,7 @@ case OP_SorterData: {
 
   pOut = &aMem[pOp->p2];
   pC = p->apCsr[pOp->p1];
-  assert( pC->isSorter );
+  assert( isSorter(pC) );
   rc = sqlite3VdbeSorterRowkey(pC, pOut);
   break;
 }
@@ -4307,9 +4252,9 @@ case OP_RowData: {
   /* Note that RowKey and RowData are really exactly the same instruction */
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
   pC = p->apCsr[pOp->p1];
-  assert( pC->isSorter==0 );
+  assert( isSorter(pC)==0 );
   assert( pC->isTable || pOp->opcode!=OP_RowData );
-  assert( pC->isIndex || pOp->opcode==OP_RowData );
+  assert( pC->isTable==0 || pOp->opcode==OP_RowData );
   assert( pC!=0 );
   assert( pC->nullRow==0 );
   assert( pC->pseudoTableReg==0 );
@@ -4326,7 +4271,7 @@ case OP_RowData: {
   rc = sqlite3VdbeCursorMoveto(pC);
   if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;
 
-  if( pC->isIndex ){
+  if( pC->isTable==0 ){
     assert( !pC->isTable );
     VVA_ONLY(rc =) sqlite3BtreeKeySize(pCrsr, &n64);
     assert( rc==SQLITE_OK );    /* True because of CursorMoveto() call above */
@@ -4346,7 +4291,7 @@ case OP_RowData: {
   }
   pOut->n = n;
   MemSetTypeFlag(pOut, MEM_Blob);
-  if( pC->isIndex ){
+  if( pC->isTable==0 ){
     rc = sqlite3BtreeKey(pCrsr, 0, n, pOut->z);
   }else{
     rc = sqlite3BtreeData(pCrsr, 0, n, pOut->z);
@@ -4419,6 +4364,7 @@ case OP_NullRow: {
   assert( pC!=0 );
   pC->nullRow = 1;
   pC->rowidIsValid = 0;
+  pC->cacheStatus = CACHE_STALE;
   assert( pC->pCursor || pC->pVtabCursor );
   if( pC->pCursor ){
     sqlite3BtreeClearCursor(pC->pCursor);
@@ -4494,7 +4440,7 @@ case OP_Rewind: {        /* jump */
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
-  assert( pC->isSorter==(pOp->opcode==OP_SorterSort) );
+  assert( isSorter(pC)==(pOp->opcode==OP_SorterSort) );
   res = 1;
   if( isSorter(pC) ){
     rc = sqlite3VdbeSorterRewind(db, pC, &res);
@@ -4502,7 +4448,6 @@ case OP_Rewind: {        /* jump */
     pCrsr = pC->pCursor;
     assert( pCrsr );
     rc = sqlite3BtreeFirst(pCrsr, &res);
-    pC->atFirst = res==0 ?1:0;
     pC->deferredMoveto = 0;
     pC->cacheStatus = CACHE_STALE;
     pC->rowidIsValid = 0;
@@ -4559,7 +4504,7 @@ case OP_Next: {        /* jump */
   if( pC==0 ){
     break;  /* See ticket #2273 */
   }
-  assert( pC->isSorter==(pOp->opcode==OP_SorterNext) );
+  assert( isSorter(pC)==(pOp->opcode==OP_SorterNext) );
   if( isSorter(pC) ){
     assert( pOp->opcode==OP_SorterNext );
     rc = sqlite3VdbeSorterNext(db, pC, &res);
@@ -4607,7 +4552,7 @@ case OP_IdxInsert: {        /* in2 */
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
-  assert( pC->isSorter==(pOp->opcode==OP_SorterInsert) );
+  assert( isSorter(pC)==(pOp->opcode==OP_SorterInsert) );
   pIn2 = &aMem[pOp->p2];
   assert( pIn2->flags & MEM_Blob );
   pCrsr = pC->pCursor;
@@ -5858,7 +5803,6 @@ case OP_VOpen: {
     pCur = allocateCursor(p, pOp->p1, 0, -1, 0);
     if( pCur ){
       pCur->pVtabCursor = pVtabCursor;
-      pCur->pModule = pVtabCursor->pVtab->pModule;
     }else{
       db->mallocFailed = 1;
       pModule->xClose(pVtabCursor);

src/vdbeInt.h

@@ -36,7 +36,7 @@ typedef struct VdbeOp Op;
 /*
 ** Boolean values
 */
-typedef unsigned char Bool;
+typedef unsigned Bool;
 
 /* Opaque type used by code in vdbesort.c */
 typedef struct VdbeSorter VdbeSorter;
@@ -53,6 +53,9 @@ typedef struct AuxData AuxData;
 ** loop over all entries of the Btree.  You can also insert new BTree
 ** entries or retrieve the key or data from the entry that the cursor
 ** is currently pointing to.
+**
+** Cursors can also point to virtual tables, sorters, or "pseudo-tables".
+** A pseudo-table is a single-row table implemented by registers.
 ** 
 ** Every cursor that the virtual machine has open is represented by an
 ** instance of the following structure.
@@ -61,30 +64,24 @@ struct VdbeCursor {
   BtCursor *pCursor;    /* The cursor structure of the backend */
   Btree *pBt;           /* Separate file holding temporary table */
   KeyInfo *pKeyInfo;    /* Info about index keys needed by index cursors */
-  int iDb;              /* Index of cursor database in db->aDb[] (or -1) */
+  int seekResult;       /* Result of previous sqlite3BtreeMoveto() */
   int pseudoTableReg;   /* Register holding pseudotable content. */
-  int nField;           /* Number of fields in the header */
-  Bool zeroed;          /* True if zeroed out and ready for reuse */
-  Bool rowidIsValid;    /* True if lastRowid is valid */
-  Bool atFirst;         /* True if pointing to first entry */
-  Bool useRandomRowid;  /* Generate new record numbers semi-randomly */
-  Bool nullRow;         /* True if pointing to a row with no data */
-  Bool deferredMoveto;  /* A call to sqlite3BtreeMoveto() is needed */
-  Bool isTable;         /* True if a table requiring integer keys */
-  Bool isIndex;         /* True if an index containing keys only - no data */
-  Bool isOrdered;       /* True if the underlying table is BTREE_UNORDERED */
-  Bool isSorter;        /* True if a new-style sorter */
-  Bool multiPseudo;     /* Multi-register pseudo-cursor */
+  i16 nField;           /* Number of fields in the header */
+  u16 nHdrParsed;       /* Number of header fields parsed so far */
+  i8 iDb;               /* Index of cursor database in db->aDb[] (or -1) */
+  u8 nullRow;           /* True if pointing to a row with no data */
+  u8 rowidIsValid;      /* True if lastRowid is valid */
+  u8 deferredMoveto;    /* A call to sqlite3BtreeMoveto() is needed */
+  Bool useRandomRowid:1;/* Generate new record numbers semi-randomly */
+  Bool isTable:1;       /* True if a table requiring integer keys */
+  Bool isOrdered:1;     /* True if the underlying table is BTREE_UNORDERED */
+  Bool multiPseudo:1;   /* Multi-register pseudo-cursor */
   sqlite3_vtab_cursor *pVtabCursor;  /* The cursor for a virtual table */
-  const sqlite3_module *pModule;     /* Module for cursor pVtabCursor */
   i64 seqCount;         /* Sequence counter */
   i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */
-  i64 lastRowid;        /* Last rowid from a Next or NextIdx operation */
+  i64 lastRowid;        /* Rowid being deleted by OP_Delete */
   VdbeSorter *pSorter;  /* Sorter object for OP_SorterOpen cursors */
 
-  /* Result of last sqlite3BtreeMoveto() done by an OP_NotExists */
-  int seekResult;
-
   /* Cached information about the header for the data record that the
   ** cursor is currently pointing to.  Only valid if cacheStatus matches
   ** Vdbe.cacheCtr.  Vdbe.cacheCtr will never take on the value of
@@ -95,10 +92,14 @@ struct VdbeCursor {
   ** be NULL.
   */
   u32 cacheStatus;      /* Cache is valid if this matches Vdbe.cacheCtr */
-  int payloadSize;      /* Total number of bytes in the record */
-  u32 *aType;           /* Type values for all entries in the record */
-  u32 *aOffset;         /* Cached offsets to the start of each columns data */
-  u8 *aRow;             /* Data for the current row, if all on one page */
+  u32 payloadSize;      /* Total number of bytes in the record */
+  u32 szRow;            /* Byte available in aRow */
+  u32 iHdrOffset;       /* Offset to next unparsed byte of the header */
+  const u8 *aRow;       /* Data for the current row, if all on one page */
+  u32 aType[1];         /* Type values for all entries in the record */
+  /* 2*nField extra array elements allocated for aType[], beyond the one
+  ** static element declared in the structure.  nField total array slots for
+  ** aType[] and nField+1 array slots for aOffset[] */
 };
 typedef struct VdbeCursor VdbeCursor;
 

src/vdbeaux.c

@@ -1674,7 +1674,7 @@ void sqlite3VdbeFreeCursor(Vdbe *p, VdbeCursor *pCx){
 #ifndef SQLITE_OMIT_VIRTUALTABLE
   if( pCx->pVtabCursor ){
     sqlite3_vtab_cursor *pVtabCursor = pCx->pVtabCursor;
-    const sqlite3_module *pModule = pCx->pModule;
+    const sqlite3_module *pModule = pVtabCursor->pVtab->pModule;
     p->inVtabMethod = 1;
     pModule->xClose(pVtabCursor);
     p->inVtabMethod = 0;
@@ -2658,7 +2658,7 @@ int sqlite3VdbeCursorMoveto(VdbeCursor *p){
 #endif
     p->deferredMoveto = 0;
     p->cacheStatus = CACHE_STALE;
-  }else if( ALWAYS(p->pCursor) ){
+  }else if( p->pCursor ){
     int hasMoved;
     int rc = sqlite3BtreeCursorHasMoved(p->pCursor, &hasMoved);
     if( rc ) return rc;
@@ -2966,15 +2966,12 @@ u32 sqlite3VdbeSerialGet(
       return 0;
     }
     default: {
+      static const u16 aFlag[] = { MEM_Blob|MEM_Ephem, MEM_Str|MEM_Ephem };
       u32 len = (serial_type-12)/2;
       pMem->z = (char *)buf;
       pMem->n = len;
       pMem->xDel = 0;
-      if( serial_type&0x01 ){
-        pMem->flags = MEM_Str | MEM_Ephem;
-      }else{
-        pMem->flags = MEM_Blob | MEM_Ephem;
-      }
+      pMem->flags = aFlag[serial_type&1];
       return len;
     }
   }

src/vdbeblob.c

@@ -64,7 +64,8 @@ static int blobSeekToRow(Incrblob *p, sqlite3_int64 iRow, char **pzErr){
 
   rc = sqlite3_step(p->pStmt);
   if( rc==SQLITE_ROW ){
-    u32 type = v->apCsr[0]->aType[p->iCol];
+    VdbeCursor *pC = v->apCsr[0];
+    u32 type = pC->aType[p->iCol];
     if( type<12 ){
       zErr = sqlite3MPrintf(p->db, "cannot open value of type %s",
           type==0?"null": type==7?"real": "integer"
@@ -73,9 +74,9 @@ static int blobSeekToRow(Incrblob *p, sqlite3_int64 iRow, char **pzErr){
       sqlite3_finalize(p->pStmt);
       p->pStmt = 0;
     }else{
-      p->iOffset = v->apCsr[0]->aOffset[p->iCol];
+      p->iOffset = pC->aType[p->iCol + pC->nField];
       p->nByte = sqlite3VdbeSerialTypeLen(type);
-      p->pCsr =  v->apCsr[0]->pCursor;
+      p->pCsr =  pC->pCursor;
       sqlite3BtreeEnterCursor(p->pCsr);
       sqlite3BtreeCacheOverflow(p->pCsr);
       sqlite3BtreeLeaveCursor(p->pCsr);

src/where.c

@@ -2756,7 +2756,7 @@ static Bitmask codeOneLoopStart(
   bRev = (pWInfo->revMask>>iLevel)&1;
   omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0 
            && (pWInfo->wctrlFlags & WHERE_FORCE_TABLE)==0;
-  VdbeNoopComment((v, "Begin WHERE-loop%d: %s",iLevel,pTabItem->pTab->zName));
+  VdbeModuleComment((v, "Begin WHERE-loop%d: %s",iLevel,pTabItem->pTab->zName));
 
   /* Create labels for the "break" and "continue" instructions
   ** for the current loop.  Jump to addrBrk to break out of a loop.
@@ -3461,7 +3461,7 @@ static Bitmask codeOneLoopStart(
     if( pAlt->wtFlags & (TERM_CODED) ) continue;
     testcase( pAlt->eOperator & WO_EQ );
     testcase( pAlt->eOperator & WO_IN );
-    VdbeNoopComment((v, "begin transitive constraint"));
+    VdbeModuleComment((v, "begin transitive constraint"));
     pEAlt = sqlite3StackAllocRaw(db, sizeof(*pEAlt));
     if( pEAlt ){
       *pEAlt = *pAlt->pExpr;
@@ -3918,10 +3918,15 @@ static int whereLoopAddBtreeIndex(
   saved_nOut = pNew->nOut;
   pNew->rSetup = 0;
   rLogSize = estLog(sqlite3LogEst(pProbe->aiRowEst[0]));
+
+  /* Consider using a skip-scan if there are no WHERE clause constraints
+  ** available for the left-most terms of the index, and if the average
+  ** number of repeats in the left-most terms is at least 50.
+  */
   if( pTerm==0
    && saved_nEq==saved_nSkip
    && saved_nEq+1<pProbe->nKeyCol
-   && pProbe->aiRowEst[saved_nEq+1]>50
+   && pProbe->aiRowEst[saved_nEq+1]>50  /* TUNING: Minimum for skip-scan */
   ){
     LogEst nIter;
     pNew->u.btree.nEq++;
@@ -5731,7 +5736,7 @@ WhereInfo *sqlite3WhereBegin(
   }
 
   /* Done. */
-  VdbeNoopComment((v, "Begin WHERE-core"));
+  VdbeModuleComment((v, "Begin WHERE-core"));
   return pWInfo;
 
   /* Jump here if malloc fails */
@@ -5758,7 +5763,7 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
 
   /* Generate loop termination code.
   */
-  VdbeNoopComment((v, "End WHERE-core"));
+  VdbeModuleComment((v, "End WHERE-core"));
   sqlite3ExprCacheClear(pParse);
   for(i=pWInfo->nLevel-1; i>=0; i--){
     int addr;
@@ -5804,7 +5809,7 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
       }
       sqlite3VdbeJumpHere(v, addr);
     }
-    VdbeNoopComment((v, "End WHERE-loop%d: %s", i,
+    VdbeModuleComment((v, "End WHERE-loop%d: %s", i,
                      pWInfo->pTabList->a[pLevel->iFrom].pTab->zName));
   }
 

test/analyze9.test

@@ -805,8 +805,9 @@ do_test 16.1 {
     ANALYZE;
   }
   set nByte2 [lindex [sqlite3_db_status db SCHEMA_USED 0] 1]
+  puts -nonewline " (nByte=$nByte nByte2=$nByte2)"
 
-  expr {$nByte2 > $nByte+900 && $nByte2 < $nByte+1050}
+  expr {$nByte2 > $nByte+900 && $nByte2 < $nByte+1100}
 } {1}
 
 #-------------------------------------------------------------------------

test/e_expr.test

@@ -1081,9 +1081,9 @@ ifcapable !icu {
 # EVIDENCE-OF: R-33693-50180 The REGEXP operator is a special syntax for
 # the regexp() user function.
 #
-# EVIDENCE-OF: R-57289-13578 If a application-defined SQL function named
-# "regexp" is added at run-time, that function will be called in order
-# to implement the REGEXP operator.
+# EVIDENCE-OF: R-65524-61849 If an application-defined SQL function
+# named "regexp" is added at run-time, then the "X REGEXP Y" operator
+# will be implemented as a call to "regexp(Y,X)".
 #
 proc regexpfunc {args} {
   eval lappend ::regexpargs $args

test/func.test

@@ -1319,6 +1319,24 @@ do_test func-29.6 {
   set x
 } {1}
 
+# The OP_Column opcode has an optimization that avoids loading content
+# for fields with content-length=0 when the content offset is on an overflow
+# page.  Make sure the optimization works.
+#
+do_execsql_test func-29.10 {
+  CREATE TABLE t29b(a,b,c,d,e,f,g,h,i);
+  INSERT INTO t29b 
+   VALUES(1, hex(randomblob(2000)), null, 0, 1, '', zeroblob(0),'x',x'01');
+  SELECT typeof(c), typeof(d), typeof(e), typeof(f),
+         typeof(g), typeof(h), typeof(i) FROM t29b;
+} {null integer integer text blob text blob}
+do_execsql_test func-29.11 {
+  SELECT length(f), length(g), length(h), length(i) FROM t29b;
+} {0 0 1 1}
+do_execsql_test func-29.12 {
+  SELECT quote(f), quote(g), quote(h), quote(i) FROM t29b;
+} {'' X'' 'x' X'01'}
+
 # EVIDENCE-OF: R-29701-50711 The unicode(X) function returns the numeric
 # unicode code point corresponding to the first character of the string
 # X.