When checking for the WHERE-clause push-down optimization, verify that

all terms of the compound inner SELECT are non-aggregate, not just the
last term.  Fix for ticket [f7f8c97e97597].

FossilOrigin-Name: adc082c1461e0237cd42653b529fbc136f5899baeff6ee32ee943d76184080c1

manifest

@@ -1,5 +1,5 @@
-C Version\s3.8.9
-D 2015-04-08T12:16:33.323
+C When\schecking\sfor\sthe\sWHERE-clause\spush-down\soptimization,\sverify\sthat\nall\sterms\sof\sthe\scompound\sinner\sSELECT\sare\snon-aggregate,\snot\sjust\sthe\nlast\sterm.\s\sFix\sfor\sticket\s[f7f8c97e97597].
+D 2017-07-17T19:25:10.921
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 00d12636df7a5b08af09116bcd6c7bfd49b8b3b4
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -167,7 +167,7 @@ F sqlite.pc.in 42b7bf0d02e08b9e77734a47798d1a55a9e0716b
 F sqlite3.1 fc7ad8990fc8409983309bb80de8c811a7506786
 F sqlite3.pc.in 48fed132e7cb71ab676105d2a4dc77127d8c1f3a
 F src/alter.c d23d6b6991f66b383934f137fd4384d93fb98c81
-F src/analyze.c 91540f835163d5369ccbae78e2e6c74d0dd53c1d
+F src/analyze.c 92d7ab85ded7d16f424ee388d250bd99c64302de
 F src/attach.c 880f9b8641a829c563e52dd13c452ce457ae4dd8
 F src/auth.c b56c78ebe40a2110fd361379f7e8162d23f92240
 F src/backup.c ff743689c4d6c5cb55ad42ed9d174b2b3e71f1e3
@@ -176,7 +176,7 @@ F src/btmutex.c 45a968cc85afed9b5e6cf55bf1f42f8d18107f79
 F src/btree.c 2caf598165f3608fde8abac2b243826616ce54b7
 F src/btree.h 969adc948e89e449220ff0ff724c94bb2a52e9f1
 F src/btreeInt.h 973a22a6fd61350b454ad614832b1f0a5e25a1e4
-F src/build.c 0419bba592c22f6d00e6d57a2ca7136720d02c1a
+F src/build.c 3d1abf90ecf488d49eb0c0a673a9b1f22b3ef4e81b1bffa6cf3dfdb832125d3c
 F src/callback.c 7b44ce59674338ad48b0e84e7b72f935ea4f68b0
 F src/complete.c 198a0066ba60ab06fc00fba1998d870a4d575463
 F src/ctime.c 98f89724adc891a1a4c655bee04e33e716e05887
@@ -230,12 +230,12 @@ F src/printf.c 8ae1fa9d30c1200a9268a390ba9e9cea9197b27a
 F src/random.c ba2679f80ec82c4190062d756f22d0c358180696
 F src/resolve.c 41aa91af56d960e9414ce1d7c17cfb68e0d1c6cb
 F src/rowset.c eccf6af6d620aaa4579bd3b72c1b6395d9e9fa1e
-F src/select.c c28c52e353287434fac8473e56ee4be848d12c9d
+F src/select.c 7922b1e1aaceb8eea4b921d0e6d062e32cfef8d897c6b30015fdd546c9b9f57f
 F src/shell.c 84a1593bd86aaa14f4da8a8f9b16fbc239d262aa
 F src/sqlite.h.in 278602140d49575e8708e643161f4263e428a02a
 F src/sqlite3.rc 992c9f5fb8285ae285d6be28240a7e8d3a7f2bad
 F src/sqlite3ext.h 17d487c3c91b0b8c584a32fbeb393f6f795eea7d
-F src/sqliteInt.h 107b02ed6c64162b653acc2368e982de529e14f6
+F src/sqliteInt.h 3b055fff776a257d0b2473edec5e121db8724c51c1034452c1be3b0faaf02f45
 F src/sqliteLimit.h 216557999cb45f2e3578ed53ebefe228d779cb46
 F src/status.c f266ad8a2892d659b74f0f50cb6a88b6e7c12179
 F src/table.c e7a09215315a978057fb42c640f890160dbcc45e
@@ -293,11 +293,11 @@ F src/update.c 3c4ecc282accf12d39edb8d524cf089645e55a13
 F src/utf.c fc6b889ba0779b7722634cdeaa25f1930d93820c
 F src/util.c 98a7627ca48ad3265b6940915a1d08355eb3fc7e
 F src/vacuum.c 9460b9de7b2d4e34b0d374894aa6c8a0632be8ec
-F src/vdbe.c 86ae6f4774410868af41bd839b72b7081ff03e78
+F src/vdbe.c 1e2abdaedcbd3697994c4f244ae388b2afbe1e1023537a78abdf0bbf70ef23a7
 F src/vdbe.h 6fc69d9c5e146302c56e163cb4b31d1ee64a18c3
-F src/vdbeInt.h 9cbaa84f53ddd2d09a0cf61a94337a3a035d08a0
+F src/vdbeInt.h d96370101d9109cc476b42951272bd660336a638a6b8ef0d72c0911d6cdffbfd
 F src/vdbeapi.c 583d56b129dd27f12bed518270de9ebe521e6a75
-F src/vdbeaux.c 413dc496248ac18eb0c19e35e86bb1ffd47b8907
+F src/vdbeaux.c c562ac4e1d5803287f5ad2718460eb7e1f22b8356b22603f67f6b849056465e1
 F src/vdbeblob.c 4f2e8e075d238392df98c5e03a64342465b03f90
 F src/vdbemem.c c0dc81285b7571b0a31c40f17846fe2397ec1cd9
 F src/vdbesort.c 919717d7599fa31d343ec28bffd0f9e91a4ff5f6
@@ -307,8 +307,8 @@ F src/vxworks.h c18586c8edc1bddbc15c004fa16aeb1e1342b4fb
 F src/wal.c 878c8e1a51cb2ec45c395d26b7d5cd9e1a098e4a
 F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4
 F src/walker.c c253b95b4ee44b21c406e2a1052636c31ea27804
-F src/where.c 85d832efa5ef57de542db7f430b72fecd3af8b38
-F src/whereInt.h cbe4aa57326998d89e7698ca65bb7c28541d483c
+F src/where.c 5e7cf96bd85f5e7cee1cce001031bc0ca1af68b8cfd07c781d1d8da7796eab34
+F src/whereInt.h 1d1fd0b3b9b56e08f5d3583c70a2c785a3c43941
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/aggnested.test b35b4cd69fc913f90d39a575e171e1116c3a4bb7
@@ -683,7 +683,7 @@ F test/join.test 52d4d49f86d0cf46926672878c4eaf0da399104a
 F test/join2.test f2171c265e57ee298a27e57e7051d22962f9f324
 F test/join3.test 6f0c774ff1ba0489e6c88a3e77b9d3528fb4fda0
 F test/join4.test 1a352e4e267114444c29266ce79e941af5885916
-F test/join5.test 5df23eba184f159ed9705a954957e765a10c141d
+F test/join5.test 8a5c0be6f0c260a5c7177c3b8f07c7856141038a
 F test/join6.test cfe6503791ceb0cbb509966740286ec423cbf10b
 F test/journal1.test 69abc726c51b4a0409189f9a85191205297c0577
 F test/journal2.test ae06f566c28552c313ded3fee79a6c69e6d049b1
@@ -698,6 +698,7 @@ F test/like.test 4f2a71d36a536233727f71995fef900756705e56
 F test/like2.test 3b2ee13149ba4a8a60b59756f4e5d345573852da
 F test/like3.test 7b0525a39e4f25c4fd113de7e2e28eb712dcdedf
 F test/limit.test 0c99a27a87b14c646a9d583c7c89fd06c352663e
+F test/limit2.test 7e7744cc548d7e4c92e1dd3edc30dd0f86adafd5
 F test/loadext.test 648cb95f324d1775c54a55c12271b2d1156b633b
 F test/loadext2.test 0408380b57adca04004247179837a18e866a74f7
 F test/lock.test b984ab9034e7389be0d863fe4e64cbbc4d2028f5
@@ -771,7 +772,7 @@ F test/notnull.test f8fcf58669ddba79274daa2770d61dfad8274f62
 F test/null.test a8b09b8ed87852742343b33441a9240022108993
 F test/numcast.test 5d126f7f581432e86a90d1e35cac625164aec4a1
 F test/openv2.test 0d3040974bf402e19b7df4b783e447289d7ab394
-F test/orderby1.test eb246e377612b21a418fbea57047ba8ea88aaa6b
+F test/orderby1.test 66ca14d7860a2da02411106968afee910ab1e657
 F test/orderby2.test bc11009f7cd99d96b1b11e57b199b00633eb5b04
 F test/orderby3.test 8619d06a3debdcd80a27c0fdea5c40b468854b99
 F test/orderby4.test 4d39bfbaaa3ae64d026ca2ff166353d2edca4ba4
@@ -839,7 +840,7 @@ F test/securedel2.test 2d54c28e46eb1fd6902089958b20b1b056c6f1c5
 F test/select1.test fc2a61f226a649393664ad54bc5376631801517c
 F test/select2.test 352480e0e9c66eda9c3044e412abdf5be0215b56
 F test/select3.test 2ce595f8fb8e2ac10071d3b4e424cadd4634a054
-F test/select4.test e20e8ce47b558de80616102ef273704cf0d48a3b
+F test/select4.test ddcaffe16252e84b85550d775b7a03bcf0d390b688122ca653d7199e469e3d5e
 F test/select5.test e758b8ef94f69b111df4cb819008856655dcd535
 F test/select6.test 39eac4a5c03650b2b473c532882273283ee8b7a0
 F test/select7.test 7fd2ef598cfabb6b9ff6ac13973b91d0527df49d
@@ -1171,7 +1172,7 @@ F test/where9.test 729c3ba9b47e8f9f1aab96bae7dad2a524f1d1a2
 F test/whereA.test 4d253178d135ec46d1671e440cd8f2b916aa6e6b
 F test/whereB.test 0def95db3bdec220a731c7e4bec5930327c1d8c5
 F test/whereC.test d6f4ecd4fa2d9429681a5b22a25d2bda8e86ab8a
-F test/whereD.test fd9120e262f9da3c45940f52aefeef4d15b904e5
+F test/whereD.test ac6926e3f518d5b75b61e81c2b7c327565e07a4bd919b6c5c3a003ca0cf19021
 F test/whereE.test b3a055eef928c992b0a33198a7b8dc10eea5ad2f
 F test/whereF.test 5b2ba0dbe8074aa13e416b37c753991f0a2492d7
 F test/whereG.test 69f5ec4b15760a8c860f80e2d55525669390aab3
@@ -1249,10 +1250,8 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 8e4ac2ce24415926247961b00a62425ae85d6ffb
-R 5875861747bb686954783d9ce4259b86
-T +bgcolor * #d0c0ff
-T +sym-release *
-T +sym-version-3.8.9 *
+P 52674f948c3e74e5cc32874d4885f2302ad1d5dd0bc45ff6bfda18cf4bea904a
+Q +ec215f94ac9748c0acd82af0cc9e7a92249462f9
+R a908a996bcff610704d1aca2821ce465
 U drh
-Z 05045ab8d5dbbaefca88cc23b8dca09c
+Z 30ce9b14a61bc1a1adc0dcec2dba7a8c

manifest.uuid

@@ -1 +1 @@
-8a8ffc862e96f57aa698f93de10dee28e69f6e09
+adc082c1461e0237cd42653b529fbc136f5899baeff6ee32ee943d76184080c1

src/analyze.c

@@ -1619,7 +1619,7 @@ static void initAvgEq(Index *pIdx){
         }
       }
 
-      if( nDist100>nSum100 ){
+      if( nDist100>nSum100 && sumEq<nRow ){
         avgEq = ((i64)100 * (nRow - sumEq))/(nDist100 - nSum100);
       }
       if( avgEq==0 ) avgEq = 1;

src/build.c

@@ -949,7 +949,11 @@ void sqlite3StartTable(
   pTable->iPKey = -1;
   pTable->pSchema = db->aDb[iDb].pSchema;
   pTable->nRef = 1;
+#ifdef SQLITE_DEFAULT_ROWEST
+  pTable->nRowLogEst = sqlite3LogEst(SQLITE_DEFAULT_ROWEST);
+#else
   pTable->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
+#endif
   assert( pParse->pNewTable==0 );
   pParse->pNewTable = pTable;
 

src/select.c

@@ -53,7 +53,9 @@ struct SortCtx {
   int regReturn;        /* Register holding block-output return address */
   int labelBkOut;       /* Start label for the block-output subroutine */
   int addrSortIndex;    /* Address of the OP_SorterOpen or OP_OpenEphemeral */
+  int labelDone;        /* Jump here when done, ex: LIMIT reached */
   u8 sortFlags;         /* Zero or more SORTFLAG_* bits */
+  u8 bOrderedInnerLoop; /* ORDER BY correctly sorts the inner loop */
 };
 #define SORTFLAG_UseSorter  0x01   /* Use SorterOpen instead of OpenEphemeral */
 
@@ -501,6 +503,7 @@ static void pushOntoSorter(
   int regRecord = ++pParse->nMem;                  /* Assembled sorter record */
   int nOBSat = pSort->nOBSat;                      /* ORDER BY terms to skip */
   int op;                            /* Opcode to add sorter record to sorter */
+  int iLimit;                        /* LIMIT counter */
 
   assert( bSeq==0 || bSeq==1 );
   if( nPrefixReg ){
@@ -510,6 +513,9 @@ static void pushOntoSorter(
     regBase = pParse->nMem + 1;
     pParse->nMem += nBase;
   }
+  assert( pSelect->iOffset==0 || pSelect->iLimit!=0 );
+  iLimit = pSelect->iOffset ? pSelect->iOffset+1 : pSelect->iLimit;
+  pSort->labelDone = sqlite3VdbeMakeLabel(v);
   sqlite3ExprCodeExprList(pParse, pSort->pOrderBy, regBase, SQLITE_ECEL_DUP);
   if( bSeq ){
     sqlite3VdbeAddOp2(v, OP_Sequence, pSort->iECursor, regBase+nExpr);
@@ -517,7 +523,6 @@ static void pushOntoSorter(
   if( nPrefixReg==0 ){
     sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+bSeq, nData);
   }
-
   sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nBase-nOBSat, regRecord);
   if( nOBSat>0 ){
     int regPrevKey;   /* The first nOBSat columns of the previous row */
@@ -552,6 +557,10 @@ static void pushOntoSorter(
     pSort->regReturn = ++pParse->nMem;
     sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
     sqlite3VdbeAddOp1(v, OP_ResetSorter, pSort->iECursor);
+    if( iLimit ){
+      sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, pSort->labelDone);
+      VdbeCoverage(v);
+    }
     sqlite3VdbeJumpHere(v, addrFirst);
     sqlite3ExprCodeMove(pParse, regBase, regPrevKey, pSort->nOBSat);
     sqlite3VdbeJumpHere(v, addrJmp);
@@ -562,17 +571,32 @@ static void pushOntoSorter(
     op = OP_IdxInsert;
   }
   sqlite3VdbeAddOp2(v, op, pSort->iECursor, regRecord);
-  if( pSelect->iLimit ){
+  if( iLimit ){
     int addr;
-    int iLimit;
-    if( pSelect->iOffset ){
-      iLimit = pSelect->iOffset+1;
-    }else{
-      iLimit = pSelect->iLimit;
-    }
+    int r1 = 0;
+    /* Fill the sorter until it contains LIMIT+OFFSET entries.  (The iLimit
+    ** register is initialized with value of LIMIT+OFFSET.)  After the sorter
+    ** fills up, delete the least entry in the sorter after each insert.
+    ** Thus we never hold more than the LIMIT+OFFSET rows in memory at once */
     addr = sqlite3VdbeAddOp3(v, OP_IfNotZero, iLimit, 0, -1); VdbeCoverage(v);
     sqlite3VdbeAddOp1(v, OP_Last, pSort->iECursor);
+    if( pSort->bOrderedInnerLoop ){
+      r1 = ++pParse->nMem;
+      sqlite3VdbeAddOp3(v, OP_Column, pSort->iECursor, nExpr, r1);
+      VdbeComment((v, "seq"));
+    }
     sqlite3VdbeAddOp1(v, OP_Delete, pSort->iECursor);
+    if( pSort->bOrderedInnerLoop ){
+      /* If the inner loop is driven by an index such that values from
+      ** the same iteration of the inner loop are in sorted order, then
+      ** immediately jump to the next iteration of an inner loop if the
+      ** entry from the current iteration does not fit into the top
+      ** LIMIT+OFFSET entries of the sorter. */
+      int iBrk = sqlite3VdbeCurrentAddr(v) + 2;
+      sqlite3VdbeAddOp3(v, OP_Eq, regBase+nExpr, iBrk, r1);
+      sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
+      VdbeCoverage(v);
+    }
     sqlite3VdbeJumpHere(v, addr);
   }
 }
@@ -1168,7 +1192,7 @@ static void generateSortTail(
   SelectDest *pDest /* Write the sorted results here */
 ){
   Vdbe *v = pParse->pVdbe;                     /* The prepared statement */
-  int addrBreak = sqlite3VdbeMakeLabel(v);     /* Jump here to exit loop */
+  int addrBreak = pSort->labelDone;            /* Jump here to exit loop */
   int addrContinue = sqlite3VdbeMakeLabel(v);  /* Jump here for next cycle */
   int addr;
   int addrOnce = 0;
@@ -1187,6 +1211,7 @@ static void generateSortTail(
   struct ExprList_item *aOutEx = p->pEList->a;
 #endif
 
+  assert( addrBreak<0 );
   if( pSort->labelBkOut ){
     sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
     sqlite3VdbeAddOp2(v, OP_Goto, 0, addrBreak);
@@ -2856,10 +2881,11 @@ static int multiSelectOrderBy(
   ** to the right and the left are evaluated, they use the correct
   ** collation.
   */
-  aPermute = sqlite3DbMallocRaw(db, sizeof(int)*nOrderBy);
+  aPermute = sqlite3DbMallocRaw(db, sizeof(int)*(nOrderBy + 1));
   if( aPermute ){
     struct ExprList_item *pItem;
-    for(i=0, pItem=pOrderBy->a; i<nOrderBy; i++, pItem++){
+    aPermute[0] = nOrderBy;
+    for(i=1, pItem=pOrderBy->a; i<=nOrderBy; i++, pItem++){
       assert( pItem->u.x.iOrderByCol>0
           && pItem->u.x.iOrderByCol<=p->pEList->nExpr );
       aPermute[i] = pItem->u.x.iOrderByCol - 1;
@@ -3723,6 +3749,83 @@ static int flattenSubquery(
 }
 #endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
 
+
+
+#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
+/*
+** Make copies of relevant WHERE clause terms of the outer query into
+** the WHERE clause of subquery.  Example:
+**
+**    SELECT * FROM (SELECT a AS x, c-d AS y FROM t1) WHERE x=5 AND y=10;
+**
+** Transformed into:
+**
+**    SELECT * FROM (SELECT a AS x, c-d AS y FROM t1 WHERE a=5 AND c-d=10)
+**     WHERE x=5 AND y=10;
+**
+** The hope is that the terms added to the inner query will make it more
+** efficient.
+**
+** Do not attempt this optimization if:
+**
+**   (1) The inner query is an aggregate.  (In that case, we'd really want
+**       to copy the outer WHERE-clause terms onto the HAVING clause of the
+**       inner query.  But they probably won't help there so do not bother.)
+**
+**   (2) The inner query is the recursive part of a common table expression.
+**
+**   (3) The inner query has a LIMIT clause (since the changes to the WHERE
+**       close would change the meaning of the LIMIT).
+**
+**   (4) The inner query is the right operand of a LEFT JOIN.  (The caller
+**       enforces this restriction since this routine does not have enough
+**       information to know.)
+**
+**   (5) The WHERE clause expression originates in the ON or USING clause
+**       of a LEFT JOIN.
+**
+** Return 0 if no changes are made and non-zero if one or more WHERE clause
+** terms are duplicated into the subquery.
+*/
+static int pushDownWhereTerms(
+  sqlite3 *db,          /* The database connection (for malloc()) */
+  Select *pSubq,        /* The subquery whose WHERE clause is to be augmented */
+  Expr *pWhere,         /* The WHERE clause of the outer query */
+  int iCursor           /* Cursor number of the subquery */
+){
+  Expr *pNew;
+  int nChng = 0;
+  Select *pX;           /* For looping over compound SELECTs in pSubq */
+  if( pWhere==0 ) return 0;
+  for(pX=pSubq; pX; pX=pX->pPrior){
+    if( (pX->selFlags & (SF_Aggregate|SF_Recursive))!=0 ){
+      testcase( pX->selFlags & SF_Aggregate );
+      testcase( pX->selFlags & SF_Recursive );
+      testcase( pX!=pSubq );
+      return 0; /* restrictions (1) and (2) */
+    }
+  }
+  if( pSubq->pLimit!=0 ){
+    return 0; /* restriction (3) */
+  }
+  while( pWhere->op==TK_AND ){
+    nChng += pushDownWhereTerms(db, pSubq, pWhere->pRight, iCursor);
+    pWhere = pWhere->pLeft;
+  }
+  if( ExprHasProperty(pWhere,EP_FromJoin) ) return 0; /* restriction 5 */
+  if( sqlite3ExprIsTableConstant(pWhere, iCursor) ){
+    nChng++;
+    while( pSubq ){
+      pNew = sqlite3ExprDup(db, pWhere, 0);
+      pNew = substExpr(db, pNew, iCursor, pSubq->pEList);
+      pSubq->pWhere = sqlite3ExprAnd(db, pSubq->pWhere, pNew);
+      pSubq = pSubq->pPrior;
+    }
+  }
+  return nChng;
+}
+#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
+
 /*
 ** Based on the contents of the AggInfo structure indicated by the first
 ** argument, this function checks if the following are true:
@@ -4685,6 +4788,94 @@ static void explainSimpleCount(
 # define explainSimpleCount(a,b,c)
 #endif
 
+#ifdef SQLITE_COUNTOFVIEW_OPTIMIZATION
+/*
+** Attempt to transform a query of the form
+**
+**    SELECT count(*) FROM (SELECT x FROM t1 UNION ALL SELECT y FROM t2)
+**
+** Into this:
+**
+**    SELECT (SELECT count(*) FROM t1)+(SELECT count(*) FROM t2)
+**
+** The transformation only works if all of the following are true:
+**
+**   *  The subquery is a UNION ALL of two or more terms
+**   *  There is no WHERE or GROUP BY or HAVING clauses on the subqueries
+**   *  The outer query is a simple count(*)
+**
+** Return TRUE if the optimization is undertaken.
+*/
+static int countOfViewOptimization(Parse *pParse, Select *p){
+  Select *pSub, *pPrior;
+  Expr *pExpr;
+  Expr *pCount;
+  sqlite3 *db;
+  if( (p->selFlags & SF_Aggregate)==0 ) return 0;   /* This is an aggregate query */
+  if( p->pEList->nExpr!=1 ) return 0;               /* Single result column */
+  pExpr = p->pEList->a[0].pExpr;
+  if( pExpr->op!=TK_AGG_FUNCTION ) return 0;        /* Result is an aggregate */
+  if( sqlite3_stricmp(pExpr->u.zToken,"count") ) return 0;  /* Must be count() */
+  if( pExpr->x.pList!=0 ) return 0;                 /* Must be count(*) */
+  if( p->pSrc->nSrc!=1 ) return 0;                  /* One table in the FROM clause */
+  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 subquery */
+  do{
+    if( pSub->op!=TK_ALL && pSub->pPrior ) return 0;  /* Must be UNION ALL */
+    if( pSub->pWhere ) return 0;                      /* No WHERE clause */
+    if( pSub->selFlags & SF_Aggregate ) return 0;     /* Not an aggregate */
+    pSub = pSub->pPrior;                              /* Repeat over compound terms */
+  }while( pSub );
+
+  /* If we reach this point, that means it is OK to perform the transformation */
+
+  db = pParse->db;
+  pCount = pExpr;
+  pExpr = 0;
+  pSub = p->pSrc->a[0].pSelect;
+  p->pSrc->a[0].pSelect = 0;
+  sqlite3SrcListDelete(db, p->pSrc);
+  p->pSrc = sqlite3DbMallocZero(pParse->db, sizeof(*p->pSrc));
+  while( pSub ){
+    Expr *pTerm;
+    pPrior = pSub->pPrior;
+    pSub->pPrior = 0;
+    pSub->pNext = 0;
+    pSub->selFlags |= SF_Aggregate;
+    pSub->selFlags &= ~SF_Compound;
+    pSub->nSelectRow = 0;
+    sqlite3ExprListDelete(db, pSub->pEList);
+    pTerm = pPrior ? sqlite3ExprDup(db, pCount, 0) : pCount;
+    pSub->pEList = sqlite3ExprListAppend(pParse, 0, pTerm);
+    pTerm = sqlite3PExpr(pParse, TK_SELECT, 0, 0, 0);
+    if( pTerm ){
+      pTerm->x.pSelect = pSub;
+      ExprSetProperty(pTerm, EP_xIsSelect|EP_Subquery);
+      sqlite3ExprSetHeightAndFlags(pParse, pTerm);
+      if( pExpr==0 ){
+        pExpr = pTerm;
+      }else{
+        pExpr = sqlite3PExpr(pParse, TK_PLUS, pTerm, pExpr, 0);
+      }
+    }else{
+      sqlite3SelectDelete(db, pSub);
+    }
+    pSub = pPrior;
+  }
+  p->pEList->a[0].pExpr = pExpr;
+  p->selFlags &= ~SF_Aggregate;
+
+#if SELECTTRACE_ENABLED
+  if( sqlite3SelectTrace & 0x400 ){
+    SELECTTRACE(0x400,pParse,p,("After count-of-view optimization:\n"));
+    sqlite3TreeViewSelect(0, p, 0);
+  }
+#endif
+  return 1;
+}
+#endif /* SQLITE_COUNTOFVIEW_OPTIMIZATION */
+
 /*
 ** Generate code for the SELECT statement given in the p argument.  
 **
@@ -4826,59 +5017,71 @@ int sqlite3Select(
         p->selFlags |= SF_Aggregate;
       }
       i = -1;
-    }else if( pTabList->nSrc==1
-           && OptimizationEnabled(db, SQLITE_SubqCoroutine)
-    ){
-      /* Implement a co-routine that will return a single row of the result
-      ** set on each invocation.
-      */
-      int addrTop = sqlite3VdbeCurrentAddr(v)+1;
-      pItem->regReturn = ++pParse->nMem;
-      sqlite3VdbeAddOp3(v, OP_InitCoroutine, pItem->regReturn, 0, addrTop);
-      VdbeComment((v, "%s", pItem->pTab->zName));
-      pItem->addrFillSub = addrTop;
-      sqlite3SelectDestInit(&dest, SRT_Coroutine, pItem->regReturn);
-      explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
-      sqlite3Select(pParse, pSub, &dest);
-      pItem->pTab->nRowLogEst = sqlite3LogEst(pSub->nSelectRow);
-      pItem->viaCoroutine = 1;
-      pItem->regResult = dest.iSdst;
-      sqlite3VdbeAddOp1(v, OP_EndCoroutine, pItem->regReturn);
-      sqlite3VdbeJumpHere(v, addrTop-1);
-      sqlite3ClearTempRegCache(pParse);
     }else{
-      /* Generate a subroutine that will fill an ephemeral table with
-      ** the content of this subquery.  pItem->addrFillSub will point
-      ** to the address of the generated subroutine.  pItem->regReturn
-      ** is a register allocated to hold the subroutine return address
-      */
-      int topAddr;
-      int onceAddr = 0;
-      int retAddr;
-      assert( pItem->addrFillSub==0 );
-      pItem->regReturn = ++pParse->nMem;
-      topAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pItem->regReturn);
-      pItem->addrFillSub = topAddr+1;
-      if( pItem->isCorrelated==0 ){
-        /* If the subquery is not correlated and if we are not inside of
-        ** a trigger, then we only need to compute the value of the subquery
-        ** once. */
-        onceAddr = sqlite3CodeOnce(pParse); VdbeCoverage(v);
-        VdbeComment((v, "materialize \"%s\"", pItem->pTab->zName));
-      }else{
-        VdbeNoopComment((v, "materialize \"%s\"", pItem->pTab->zName));
+      if( (pItem->jointype & JT_OUTER)==0
+       && pushDownWhereTerms(db, pSub, p->pWhere, pItem->iCursor)
+      ){
+#if SELECTTRACE_ENABLED
+        if( sqlite3SelectTrace & 0x100 ){
+          sqlite3DebugPrintf("After WHERE-clause push-down:\n");
+          sqlite3TreeViewSelect(0, p, 0);
+        }
+#endif
+      }
+      if( pTabList->nSrc==1
+       && OptimizationEnabled(db, SQLITE_SubqCoroutine)
+      ){
+        /* Implement a co-routine that will return a single row of the result
+        ** set on each invocation.
+        */
+        int addrTop = sqlite3VdbeCurrentAddr(v)+1;
+        pItem->regReturn = ++pParse->nMem;
+        sqlite3VdbeAddOp3(v, OP_InitCoroutine, pItem->regReturn, 0, addrTop);
+        VdbeComment((v, "%s", pItem->pTab->zName));
+        pItem->addrFillSub = addrTop;
+        sqlite3SelectDestInit(&dest, SRT_Coroutine, pItem->regReturn);
+        explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
+        sqlite3Select(pParse, pSub, &dest);
+        pItem->pTab->nRowLogEst = sqlite3LogEst(pSub->nSelectRow);
+        pItem->viaCoroutine = 1;
+        pItem->regResult = dest.iSdst;
+        sqlite3VdbeAddOp1(v, OP_EndCoroutine, pItem->regReturn);
+        sqlite3VdbeJumpHere(v, addrTop-1);
+        sqlite3ClearTempRegCache(pParse);
+      }else{
+        /* Generate a subroutine that will fill an ephemeral table with
+        ** the content of this subquery.  pItem->addrFillSub will point
+        ** to the address of the generated subroutine.  pItem->regReturn
+        ** is a register allocated to hold the subroutine return address
+        */
+        int topAddr;
+        int onceAddr = 0;
+        int retAddr;
+        assert( pItem->addrFillSub==0 );
+        pItem->regReturn = ++pParse->nMem;
+        topAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pItem->regReturn);
+        pItem->addrFillSub = topAddr+1;
+        if( pItem->isCorrelated==0 ){
+          /* If the subquery is not correlated and if we are not inside of
+          ** a trigger, then we only need to compute the value of the subquery
+          ** once. */
+          onceAddr = sqlite3CodeOnce(pParse); VdbeCoverage(v);
+          VdbeComment((v, "materialize \"%s\"", pItem->pTab->zName));
+        }else{
+          VdbeNoopComment((v, "materialize \"%s\"", pItem->pTab->zName));
+        }
+        sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);
+        explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
+        sqlite3Select(pParse, pSub, &dest);
+        pItem->pTab->nRowLogEst = sqlite3LogEst(pSub->nSelectRow);
+        if( onceAddr ) sqlite3VdbeJumpHere(v, onceAddr);
+        retAddr = sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn);
+        VdbeComment((v, "end %s", pItem->pTab->zName));
+        sqlite3VdbeChangeP1(v, topAddr, retAddr);
+        sqlite3ClearTempRegCache(pParse);
       }
-      sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);
-      explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
-      sqlite3Select(pParse, pSub, &dest);
-      pItem->pTab->nRowLogEst = sqlite3LogEst(pSub->nSelectRow);
-      if( onceAddr ) sqlite3VdbeJumpHere(v, onceAddr);
-      retAddr = sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn);
-      VdbeComment((v, "end %s", pItem->pTab->zName));
-      sqlite3VdbeChangeP1(v, topAddr, retAddr);
-      sqlite3ClearTempRegCache(pParse);
     }
-    if( /*pParse->nErr ||*/ db->mallocFailed ){
+    if( db->mallocFailed ){
       goto select_end;
     }
     pParse->nHeight -= sqlite3SelectExprHeight(p);
@@ -4908,6 +5111,16 @@ int sqlite3Select(
   }
 #endif
 
+#ifdef SQLITE_COUNTOFVIEW_OPTIMIZATION
+  if( OptimizationEnabled(db, SQLITE_QueryFlattener|SQLITE_CountOfView)
+   && countOfViewOptimization(pParse, p)
+  ){
+    if( db->mallocFailed ) goto select_end;
+    pEList = p->pEList;
+    pTabList = p->pSrc;
+  }
+#endif
+
   /* If the query is DISTINCT with an ORDER BY but is not an aggregate, and 
   ** if the select-list is the same as the ORDER BY list, then this query
   ** can be rewritten as a GROUP BY. In other words, this:
@@ -5001,6 +5214,7 @@ int sqlite3Select(
     }
     if( sSort.pOrderBy ){
       sSort.nOBSat = sqlite3WhereIsOrdered(pWInfo);
+      sSort.bOrderedInnerLoop = sqlite3WhereOrderedInnerLoop(pWInfo);
       if( sSort.nOBSat==sSort.pOrderBy->nExpr ){
         sSort.pOrderBy = 0;
       }

src/sqliteInt.h

@@ -1245,6 +1245,7 @@ struct sqlite3 {
 #define SQLITE_Transitive     0x0200   /* Transitive constraints */
 #define SQLITE_OmitNoopJoin   0x0400   /* Omit unused tables in joins */
 #define SQLITE_Stat34         0x0800   /* Use STAT3 or STAT4 data */
+#define SQLITE_CountOfView    0x1000   /* The count-of-view optimization */
 #define SQLITE_AllOpts        0xffff   /* All optimizations */
 
 /*
@@ -2276,6 +2277,7 @@ struct SrcList {
 #define WHERE_WANT_DISTINCT    0x0400 /* All output needs to be distinct */
 #define WHERE_SORTBYGROUP      0x0800 /* Support sqlite3WhereIsSorted() */
 #define WHERE_REOPEN_IDX       0x1000 /* Try to use OP_ReopenIdx */
+#define WHERE_ORDERBY_LIMIT    0x2000 /* ORDERBY+LIMIT on the inner loop */
 
 /* Allowed return values from sqlite3WhereIsDistinct()
 */
@@ -3289,6 +3291,7 @@ void sqlite3WhereEnd(WhereInfo*);
 u64 sqlite3WhereOutputRowCount(WhereInfo*);
 int sqlite3WhereIsDistinct(WhereInfo*);
 int sqlite3WhereIsOrdered(WhereInfo*);
+int sqlite3WhereOrderedInnerLoop(WhereInfo*);
 int sqlite3WhereIsSorted(WhereInfo*);
 int sqlite3WhereContinueLabel(WhereInfo*);
 int sqlite3WhereBreakLabel(WhereInfo*);

src/vdbe.c

@@ -1980,11 +1980,14 @@ case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
 ** The permutation is only valid until the next OP_Compare that has
 ** the OPFLAG_PERMUTE bit set in P5. Typically the OP_Permutation should 
 ** occur immediately prior to the OP_Compare.
+**
+** The first integer in the P4 integer array is the length of the array
+** and does not become part of the permutation.
 */
 case OP_Permutation: {
   assert( pOp->p4type==P4_INTARRAY );
   assert( pOp->p4.ai );
-  aPermute = pOp->p4.ai;
+  aPermute = pOp->p4.ai + 1;
   break;
 }
 
@@ -2290,12 +2293,16 @@ case OP_Column: {
   u16 fx;            /* pDest->flags value */
   Mem *pReg;         /* PseudoTable input register */
 
+  pC = p->apCsr[pOp->p1];
   p2 = pOp->p2;
+
+  /* If the cursor cache is stale, bring it up-to-date */
+  rc = sqlite3VdbeCursorMoveto(&pC, &p2);
+
   assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
   pDest = &aMem[pOp->p3];
   memAboutToChange(p, pDest);
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
   assert( p2<pC->nField );
   aOffset = pC->aOffset;
@@ -2306,8 +2313,6 @@ case OP_Column: {
   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 ){
     if( pC->nullRow ){
@@ -3725,7 +3730,7 @@ case OP_SeekGT: {       /* jump, in3 */
   break;
 }
 
-/* Opcode: Seek P1 P2 * * *
+/* Opcode: Seek P1 P2 P3 P4 *
 ** Synopsis:  intkey=r[P2]
 **
 ** P1 is an open table cursor and P2 is a rowid integer.  Arrange
@@ -3734,6 +3739,13 @@ case OP_SeekGT: {       /* jump, in3 */
 ** This is actually a deferred seek.  Nothing actually happens until
 ** the cursor is used to read a record.  That way, if no reads
 ** occur, no unnecessary I/O happens.
+**
+** P4 may contain an array of integers (type P4_INTARRAY) containing
+** one entry for each column in the table P1 is open on. If so, then
+** parameter P3 is a cursor open on a database index. If array entry
+** a[i] is non-zero, then reading column (a[i]-1) from cursor P3 is 
+** equivalent to performing the deferred seek and then reading column i 
+** from P1.
 */
 case OP_Seek: {    /* in2 */
   VdbeCursor *pC;
@@ -3747,6 +3759,9 @@ case OP_Seek: {    /* in2 */
   pIn2 = &aMem[pOp->p2];
   pC->movetoTarget = sqlite3VdbeIntValue(pIn2);
   pC->deferredMoveto = 1;
+  assert( pOp->p4type==P4_INTARRAY || pOp->p4.ai==0 );
+  pC->aAltMap = pOp->p4.ai;
+  pC->pAltCursor = p->apCsr[pOp->p3];
   break;
 }
   

src/vdbeInt.h

@@ -60,6 +60,7 @@ typedef struct AuxData AuxData;
 ** Every cursor that the virtual machine has open is represented by an
 ** instance of the following structure.
 */
+typedef struct VdbeCursor VdbeCursor;
 struct VdbeCursor {
   BtCursor *pCursor;    /* The cursor structure of the backend */
   Btree *pBt;           /* Separate file holding temporary table */
@@ -83,6 +84,11 @@ struct VdbeCursor {
   i64 seqCount;         /* Sequence counter */
   i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */
   VdbeSorter *pSorter;  /* Sorter object for OP_SorterOpen cursors */
+  VdbeCursor *pAltCursor; /* Associated index cursor from which to read */
+  int *aAltMap;           /* Mapping from table to index column numbers */
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+  u64 maskUsed;         /* Mask of columns used by this cursor */
+#endif
 
   /* Cached information about the header for the data record that the
   ** cursor is currently pointing to.  Only valid if cacheStatus matches
@@ -104,7 +110,6 @@ struct VdbeCursor {
   ** static element declared in the structure.  nField total array slots for
   ** aType[] and nField+1 array slots for aOffset[] */
 };
-typedef struct VdbeCursor VdbeCursor;
 
 /*
 ** When a sub-program is executed (OP_Program), a structure of this type
@@ -393,7 +398,7 @@ struct Vdbe {
 */
 void sqlite3VdbeFreeCursor(Vdbe *, VdbeCursor*);
 void sqliteVdbePopStack(Vdbe*,int);
-int sqlite3VdbeCursorMoveto(VdbeCursor*);
+int sqlite3VdbeCursorMoveto(VdbeCursor**, int*);
 int sqlite3VdbeCursorRestore(VdbeCursor*);
 #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
 void sqlite3VdbePrintOp(FILE*, int, Op*);

src/vdbeaux.c

@@ -1123,7 +1123,21 @@ static char *displayP4(Op *pOp, char *zTemp, int nTemp){
     }
 #endif
     case P4_INTARRAY: {
-      sqlite3_snprintf(nTemp, zTemp, "intarray");
+      int i, j;
+      int *ai = pOp->p4.ai;
+      int n = ai[0];   /* The first element of an INTARRAY is always the
+                       ** count of the number of elements to follow */
+      zTemp[0] = '[';
+      for(i=j=1; i<n && j<nTemp-7; i++){
+        if( j>1 ) zTemp[j++] = ',';
+        sqlite3_snprintf(nTemp-j, zTemp+j, "%d", ai[i]);
+        j += sqlite3Strlen30(zTemp+j);
+      }
+      if( i<n ){
+        memcpy(zTemp+j, ",...]", 6);
+      }else{
+        memcpy(zTemp+j, "]", 2);
+      }
       break;
     }
     case P4_SUBPROGRAM: {
@@ -2818,8 +2832,15 @@ int sqlite3VdbeCursorRestore(VdbeCursor *p){
 ** If the cursor is already pointing to the correct row and that row has
 ** not been deleted out from under the cursor, then this routine is a no-op.
 */
-int sqlite3VdbeCursorMoveto(VdbeCursor *p){
+int sqlite3VdbeCursorMoveto(VdbeCursor **pp, int *piCol){
+  VdbeCursor *p = *pp;
   if( p->deferredMoveto ){
+    int iMap;
+    if( p->aAltMap && (iMap = p->aAltMap[1+*piCol])>0 ){
+      *pp = p->pAltCursor;
+      *piCol = iMap - 1;
+      return SQLITE_OK;
+    }
     return handleDeferredMoveto(p);
   }
   if( p->pCursor && sqlite3BtreeCursorHasMoved(p->pCursor) ){

src/where.c

@@ -42,6 +42,18 @@ int sqlite3WhereIsOrdered(WhereInfo *pWInfo){
   return pWInfo->nOBSat;
 }
 
+/*
+** Return TRUE if the innermost loop of the WHERE clause implementation
+** returns rows in ORDER BY order for complete run of the inner loop.
+**
+** Across multiple iterations of outer loops, the output rows need not be
+** sorted.  As long as rows are sorted for just the innermost loop, this
+** routine can return TRUE.
+*/
+int sqlite3WhereOrderedInnerLoop(WhereInfo *pWInfo){
+  return pWInfo->bOrderedInnerLoop;
+}
+
 /*
 ** Return the VDBE address or label to jump to in order to continue
 ** immediately with the next row of a WHERE clause.
@@ -2209,7 +2221,7 @@ static int whereKeyStats(
       iGap = iGap/3;
     }
     aStat[0] = iLower + iGap;
-    aStat[1] = pIdx->aAvgEq[iCol];
+    aStat[1] = pIdx->aAvgEq[nField-1];
   }
 
   /* Restore the pRec->nField value before returning.  */
@@ -3236,6 +3248,55 @@ static void whereLikeOptimizationStringFixup(
   }
 }
 
+/*
+** Cursor iCur is open on an intkey b-tree (a table). Register iRowid contains
+** a rowid value just read from cursor iIdxCur, open on index pIdx. This
+** function generates code to do a deferred seek of cursor iCur to the 
+** rowid stored in register iRowid.
+**
+** Normally, this is just:
+**
+**   OP_Seek $iCur $iRowid
+**
+** However, if the scan currently being coded is a branch of an OR-loop and
+** the statement currently being coded is a SELECT, then P3 of the OP_Seek
+** is set to iIdxCur and P4 is set to point to an array of integers
+** containing one entry for each column of the table cursor iCur is open 
+** on. For each table column, if the column is the i'th column of the 
+** index, then the corresponding array entry is set to (i+1). If the column
+** does not appear in the index at all, the array entry is set to 0.
+*/
+static void codeDeferredSeek(
+  WhereInfo *pWInfo,              /* Where clause context */
+  Index *pIdx,                    /* Index scan is using */
+  int iCur,                       /* Cursor for IPK b-tree */
+  int iRowid,                     /* Register containing rowid to seek to */
+  int iIdxCur                     /* Index cursor */
+){
+  Parse *pParse = pWInfo->pParse; /* Parse context */
+  Vdbe *v = pParse->pVdbe;        /* Vdbe to generate code within */
+
+  assert( iIdxCur>0 );
+  assert( pIdx->aiColumn[pIdx->nColumn-1]==-1 );
+  
+  sqlite3VdbeAddOp3(v, OP_Seek, iCur, iRowid, iIdxCur);
+  if( (pWInfo->wctrlFlags & WHERE_FORCE_TABLE)
+   && DbMaskAllZero(sqlite3ParseToplevel(pParse)->writeMask)
+  ){
+    int i;
+    Table *pTab = pIdx->pTable;
+    int *ai = (int*)sqlite3DbMallocZero(pParse->db, sizeof(int)*(pTab->nCol+1));
+    if( ai ){
+      ai[0] = pTab->nCol;
+      for(i=0; i<pIdx->nColumn-1; i++){
+        assert( pIdx->aiColumn[i]<pTab->nCol );
+        if( pIdx->aiColumn[i]>=0 ) ai[pIdx->aiColumn[i]+1] = i+1;
+      }
+      sqlite3VdbeChangeP4(v, -1, (char*)ai, P4_INTARRAY);
+    }
+  }
+}
+
 /*
 ** Generate code for the start of the iLevel-th loop in the WHERE clause
 ** implementation described by pWInfo.
@@ -3714,7 +3775,7 @@ static Bitmask codeOneLoopStart(
       iRowidReg = ++pParse->nMem;
       sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
       sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
-      sqlite3VdbeAddOp2(v, OP_Seek, iCur, iRowidReg);  /* Deferred seek */
+      codeDeferredSeek(pWInfo, pIdx, iCur, iRowidReg, iIdxCur);
     }else if( iCur!=iIdxCur ){
       Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
       iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);
@@ -5602,7 +5663,7 @@ static i8 wherePathSatisfiesOrderBy(
   WhereInfo *pWInfo,    /* The WHERE clause */
   ExprList *pOrderBy,   /* ORDER BY or GROUP BY or DISTINCT clause to check */
   WherePath *pPath,     /* The WherePath to check */
-  u16 wctrlFlags,       /* Might contain WHERE_GROUPBY or WHERE_DISTINCTBY */
+  u16 wctrlFlags,       /* WHERE_GROUPBY, _DISTINCTBY  or _ORDERBY_LIMIT */
   u16 nLoop,            /* Number of entries in pPath->aLoop[] */
   WhereLoop *pLast,     /* Add this WhereLoop to the end of pPath->aLoop[] */
   Bitmask *pRevMask     /* OUT: Mask of WhereLoops to run in reverse order */
@@ -5613,6 +5674,7 @@ static i8 wherePathSatisfiesOrderBy(
   u8 isOrderDistinct;   /* All prior WhereLoops are order-distinct */
   u8 distinctColumns;   /* True if the loop has UNIQUE NOT NULL columns */
   u8 isMatch;           /* iColumn matches a term of the ORDER BY clause */
+  u16 eqOpMask;         /* Allowed equality operators */
   u16 nKeyCol;          /* Number of key columns in pIndex */
   u16 nColumn;          /* Total number of ordered columns in the index */
   u16 nOrderBy;         /* Number terms in the ORDER BY clause */
@@ -5663,8 +5725,16 @@ static i8 wherePathSatisfiesOrderBy(
   obDone = MASKBIT(nOrderBy)-1;
   orderDistinctMask = 0;
   ready = 0;
+  eqOpMask = WO_EQ | WO_ISNULL;
+  if( wctrlFlags & WHERE_ORDERBY_LIMIT ) eqOpMask |= WO_IN;
   for(iLoop=0; isOrderDistinct && obSat<obDone && iLoop<=nLoop; iLoop++){
     if( iLoop>0 ) ready |= pLoop->maskSelf;
+    if( iLoop<nLoop ){
+      pLoop = pPath->aLoop[iLoop];
+      if( wctrlFlags & WHERE_ORDERBY_LIMIT ) continue;
+    }else{
+      pLoop = pLast;
+    }
     pLoop = iLoop<nLoop ? pPath->aLoop[iLoop] : pLast;
     if( pLoop->wsFlags & WHERE_VIRTUALTABLE ){
       if( pLoop->u.vtab.isOrdered ) obSat = obDone;
@@ -5683,8 +5753,16 @@ static i8 wherePathSatisfiesOrderBy(
       if( pOBExpr->op!=TK_COLUMN ) continue;
       if( pOBExpr->iTable!=iCur ) continue;
       pTerm = findTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
-                       ~ready, WO_EQ|WO_ISNULL, 0);
+                       ~ready, eqOpMask, 0);
       if( pTerm==0 ) continue;
+      if( pTerm->eOperator==WO_IN ){
+        /* IN terms are only valid for sorting in the ORDER BY LIMIT 
+        ** optimization, and then only if they are actually used
+        ** by the query plan */
+        assert( wctrlFlags & WHERE_ORDERBY_LIMIT );
+        for(j=0; j<pLoop->nLTerm && pTerm!=pLoop->aLTerm[j]; j++){}
+        if( j>=pLoop->nLTerm ) continue;
+      }
       if( (pTerm->eOperator&WO_EQ)!=0 && pOBExpr->iColumn>=0 ){
         const char *z1, *z2;
         pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
@@ -5721,10 +5799,12 @@ static i8 wherePathSatisfiesOrderBy(
       for(j=0; j<nColumn; j++){
         u8 bOnce;   /* True to run the ORDER BY search loop */
 
-        /* Skip over == and IS NULL terms */
+        /* Skip over == and IS NULL terms
+        ** (Also skip IN terms when doing WHERE_ORDERBY_LIMIT processing)
+        */
         if( j<pLoop->u.btree.nEq
          && pLoop->nSkip==0
-         && ((i = pLoop->aLTerm[j]->eOperator) & (WO_EQ|WO_ISNULL))!=0
+         && ((i = pLoop->aLTerm[j]->eOperator) & eqOpMask)!=0
         ){
           if( i & WO_ISNULL ){
             testcase( isOrderDistinct );
@@ -6090,8 +6170,8 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
             ** this candidate as not viable. */
 #ifdef WHERETRACE_ENABLED /* 0x4 */
             if( sqlite3WhereTrace&0x4 ){
-              sqlite3DebugPrintf("Skip   %s cost=%-3d,%3d order=%c\n",
-                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+              sqlite3DebugPrintf("Skip   %s cost=%-3d,%3d,%3d order=%c\n",
+                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,
                   isOrdered>=0 ? isOrdered+'0' : '?');
             }
 #endif
@@ -6109,26 +6189,36 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
           pTo = &aTo[jj];
 #ifdef WHERETRACE_ENABLED /* 0x4 */
           if( sqlite3WhereTrace&0x4 ){
-            sqlite3DebugPrintf("New    %s cost=%-3d,%3d order=%c\n",
-                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+            sqlite3DebugPrintf("New    %s cost=%-3d,%3d,%3d order=%c\n",
+                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,
                 isOrdered>=0 ? isOrdered+'0' : '?');
           }
 #endif
         }else{
           /* Control reaches here if best-so-far path pTo=aTo[jj] covers the
-          ** same set of loops and has the sam isOrdered setting as the
+          ** same set of loops and has the same isOrdered setting as the
           ** candidate path.  Check to see if the candidate should replace
-          ** pTo or if the candidate should be skipped */
-          if( pTo->rCost<rCost || (pTo->rCost==rCost && pTo->nRow<=nOut) ){
+          ** pTo or if the candidate should be skipped.
+          ** 
+          ** The conditional is an expanded vector comparison equivalent to:
+          **   (pTo->rCost,pTo->nRow,pTo->rUnsorted) <= (rCost,nOut,rUnsorted)
+          */
+          if( pTo->rCost<rCost 
+           || (pTo->rCost==rCost
+               && (pTo->nRow<nOut
+                   || (pTo->nRow==nOut && pTo->rUnsorted<=rUnsorted)
+                  )
+              )
+          ){
 #ifdef WHERETRACE_ENABLED /* 0x4 */
             if( sqlite3WhereTrace&0x4 ){
               sqlite3DebugPrintf(
-                  "Skip   %s cost=%-3d,%3d order=%c",
-                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+                  "Skip   %s cost=%-3d,%3d,%3d order=%c",
+                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,
                   isOrdered>=0 ? isOrdered+'0' : '?');
-              sqlite3DebugPrintf("   vs %s cost=%-3d,%d order=%c\n",
+              sqlite3DebugPrintf("   vs %s cost=%-3d,%3d,%3d order=%c\n",
                   wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
-                  pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
+                  pTo->rUnsorted, pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
             }
 #endif
             /* Discard the candidate path from further consideration */
@@ -6141,12 +6231,12 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
 #ifdef WHERETRACE_ENABLED /* 0x4 */
           if( sqlite3WhereTrace&0x4 ){
             sqlite3DebugPrintf(
-                "Update %s cost=%-3d,%3d order=%c",
-                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+                "Update %s cost=%-3d,%3d,%3d order=%c",
+                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted,
                 isOrdered>=0 ? isOrdered+'0' : '?');
-            sqlite3DebugPrintf("  was %s cost=%-3d,%3d order=%c\n",
+            sqlite3DebugPrintf("  was %s cost=%-3d,%3d,%3d order=%c\n",
                 wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
-                pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
+                pTo->rUnsorted, pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
           }
 #endif
         }
@@ -6237,8 +6327,19 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
       }
     }else{
       pWInfo->nOBSat = pFrom->isOrdered;
-      if( pWInfo->nOBSat<0 ) pWInfo->nOBSat = 0;
       pWInfo->revMask = pFrom->revLoop;
+      if( pWInfo->nOBSat<=0 ){
+        pWInfo->nOBSat = 0;
+        if( nLoop>0 && (pFrom->aLoop[nLoop-1]->wsFlags & WHERE_ONEROW)==0 ){
+          Bitmask m = 0;
+          int rc = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy, pFrom,
+                      WHERE_ORDERBY_LIMIT, nLoop-1, pFrom->aLoop[nLoop-1], &m);
+          if( rc==pWInfo->pOrderBy->nExpr ){
+            pWInfo->bOrderedInnerLoop = 1;
+            pWInfo->revMask = m;
+          }
+        }
+      }
     }
     if( (pWInfo->wctrlFlags & WHERE_SORTBYGROUP)
         && pWInfo->nOBSat==pWInfo->pOrderBy->nExpr

src/whereInt.h

@@ -412,6 +412,7 @@ struct WhereInfo {
   u8 untestedTerms;         /* Not all WHERE terms resolved by outer loop */
   u8 eDistinct;             /* One of the WHERE_DISTINCT_* values below */
   u8 nLevel;                /* Number of nested loop */
+  u8 bOrderedInnerLoop;     /* True if only the inner-most loop is ordered */
   int iTop;                 /* The very beginning of the WHERE loop */
   int iContinue;            /* Jump here to continue with next record */
   int iBreak;               /* Jump here to break out of the loop */

test/join5.test

@@ -161,4 +161,27 @@ do_execsql_test join5-3.3 {
   SELECT * FROM x1 LEFT JOIN x2 JOIN x3 WHERE x3.d = x2.b;
 } {}
 
+# Ticket https://www.sqlite.org/src/tktview/c2a19d81652f40568c770c43 on
+# 2015-08-20.  LEFT JOIN and the push-down optimization.
+#
+do_execsql_test join6-4.1 {
+  SELECT *
+  FROM (
+      SELECT 'apple' fruit
+      UNION ALL SELECT 'banana'
+  ) a
+  JOIN (
+      SELECT 'apple' fruit
+      UNION ALL SELECT 'banana'
+  ) b ON a.fruit=b.fruit
+  LEFT JOIN (
+      SELECT 1 isyellow
+  ) c ON b.fruit='banana';
+} {apple apple {} banana banana 1}
+do_execsql_test join6-4.2 {
+  SELECT *
+    FROM (SELECT 'apple' fruit UNION ALL SELECT 'banana')
+         LEFT JOIN (SELECT 1) ON fruit='banana';
+} {apple {} banana 1}
+
 finish_test

test/limit2.test

@@ -0,0 +1,123 @@
+# 2016-05-20
+#
+# 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.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the LIMIT in combination with ORDER BY
+# and in particular, the optimizations in the inner loop that cause an
+# early exit of the inner loop when the LIMIT is reached and the inner
+# loop is emitting rows in ORDER BY order.
+
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+do_execsql_test limit2-100 {
+  CREATE TABLE t1(a,b);
+  WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<1000)
+    INSERT INTO t1(a,b) SELECT 1, (x*17)%1000 + 1000 FROM c;
+  INSERT INTO t1(a,b) VALUES(2,2),(3,1006),(4,4),(5,9999);
+  CREATE INDEX t1ab ON t1(a,b);
+}
+set sqlite_search_count 0
+do_execsql_test limit2-100.1 {
+  SELECT a, b, '|' FROM t1 WHERE a IN (2,4,5,3,1) ORDER BY b LIMIT 5;
+} {2 2 | 4 4 | 1 1000 | 1 1001 | 1 1002 |}
+set fast_count $sqlite_search_count
+set sqlite_search_count 0
+do_execsql_test limit2-100.2 {
+  SELECT a, b, '|' FROM t1 WHERE a IN (2,4,5,3,1) ORDER BY +b LIMIT 5;
+} {2 2 | 4 4 | 1 1000 | 1 1001 | 1 1002 |}
+do_test limit2-100.3 {
+  set slow_count $sqlite_search_count
+  expr {$fast_count < 0.02*$slow_count}
+} {1}
+
+do_execsql_test limit2-110 {
+  CREATE TABLE t2(x,y);
+  INSERT INTO t2(x,y) VALUES('a',1),('a',2),('a',3),('a',4);
+  INSERT INTO t2(x,y) VALUES('b',1),('c',2),('d',3),('e',4);
+  CREATE INDEX t2xy ON t2(x,y);
+}
+set sqlite_search_count 0
+do_execsql_test limit2-110.1 {
+  SELECT a, b, '|' FROM t2, t1 WHERE t2.x='a' AND t1.a=t2.y ORDER BY t1.b LIMIT 5;
+} {2 2 | 4 4 | 1 1000 | 1 1001 | 1 1002 |}
+set fast_count $sqlite_search_count
+set sqlite_search_count 0
+do_execsql_test limit2-110.2 {
+  SELECT a, b, '|' FROM t2, t1 WHERE t2.x='a' AND t1.a=t2.y ORDER BY +t1.b LIMIT 5;
+} {2 2 | 4 4 | 1 1000 | 1 1001 | 1 1002 |}
+set slow_count $sqlite_search_count
+do_test limit2-110.3 {
+  expr {$fast_count < 0.02*$slow_count}
+} {1}
+
+do_execsql_test limit2-120 {
+  DROP INDEX t1ab;
+  CREATE INDEX t1ab ON t1(a,b DESC);
+}
+set sqlite_search_count 0
+do_execsql_test limit2-120.1 {
+  SELECT a, b, '|' FROM t1 WHERE a IN (2,4,5,3,1) ORDER BY b DESC LIMIT 5;
+} {5 9999 | 1 1999 | 1 1998 | 1 1997 | 1 1996 |}
+set fast_count $sqlite_search_count
+set sqlite_search_count 0
+do_execsql_test limit2-120.2 {
+  SELECT a, b, '|' FROM t1 WHERE a IN (2,4,5,3,1) ORDER BY +b DESC LIMIT 5;
+} {5 9999 | 1 1999 | 1 1998 | 1 1997 | 1 1996 |}
+do_test limit2-120.3 {
+  set slow_count $sqlite_search_count
+  expr {$fast_count < 0.02*$slow_count}
+} {1}
+
+# Bug report against the new ORDER BY LIMIT optimization just prior to
+# release.  (Unreleased so there is no ticket).
+#
+# Make sure the optimization is not applied if the inner loop can only
+# provide a single row of output.
+#
+do_execsql_test limit2-200 {
+  CREATE TABLE t200(a, b);
+  WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<1000)
+    INSERT INTO t200(a,b) SELECT x, x FROM c;
+  CREATE TABLE t201(x INTEGER PRIMARY KEY, y);
+  INSERT INTO t201(x,y) VALUES(2,12345);
+
+  SELECT *, '|' FROM t200, t201 WHERE x=b ORDER BY y LIMIT 3;
+} {2 2 2 12345 |}
+do_execsql_test limit2-210 {
+  SELECT *, '|' FROM t200 LEFT JOIN t201 ON x=b ORDER BY y LIMIT 3;
+} {1 1 {} {} | 3 3 {} {} | 4 4 {} {} |}
+
+# Bug in the ORDER BY LIMIT optimization reported on 2016-09-06.
+# Ticket https://www.sqlite.org/src/info/559733b09e96
+#
+do_execsql_test limit2-300 {
+  CREATE TABLE t300(a,b,c);
+  CREATE INDEX t300x ON t300(a,b,c);
+  INSERT INTO t300 VALUES(0,1,99),(0,1,0),(0,0,0);
+  SELECT *,'.' FROM t300 WHERE a=0 AND (c=0 OR c=99) ORDER BY c DESC;
+} {0 1 99 . 0 0 0 . 0 1 0 .}
+do_execsql_test limit2-310 {
+  SELECT *,'.' FROM t300 WHERE a=0 AND (c=0 OR c=99) ORDER BY c DESC LIMIT 1;
+} {0 1 99 .}
+
+# Make sure the SELECT loop is ordered correctly for the direction of
+# the ORDER BY
+#
+do_execsql_test limit2-400 {
+  CREATE TABLE t400(a,b);
+  CREATE INDEX t400_ab ON t400(a,b);
+  INSERT INTO t400(a,b) VALUES(1,90),(1,40),(2,80),(2,30),(3,70),(3,20);
+  SELECT *,'x' FROM t400 WHERE a IN (1,2,3) ORDER BY b DESC LIMIT 3;
+  SELECT *,'y' FROM t400 WHERE a IN (1,2,3) ORDER BY +b DESC LIMIT 3;
+} {1 90 x 2 80 x 3 70 x 1 90 y 2 80 y 3 70 y}
+
+finish_test

test/orderby1.test

@@ -496,4 +496,21 @@ do_execsql_test 7.0 {
 } {~/ORDER BY/}
 
 
+#---------------------------------------------------------------------------
+# https://www.sqlite.org/src/tktview/cb3aa0641d9a413841c004293a4fc06cdc122029
+#
+# Adverse interaction between scalar subqueries and the partial-sorting
+# logic.
+#
+do_execsql_test 9.0 {
+  DROP TABLE IF EXISTS t1;
+  CREATE TABLE t1(x INTEGER PRIMARY KEY);
+  INSERT INTO t1 VALUES(1),(2);
+  DROP TABLE IF EXISTS t2;
+  CREATE TABLE t2(y);
+  INSERT INTO t2 VALUES(9),(8),(3),(4);
+  SELECT (SELECT x||y FROM t2, t1 ORDER BY x, y);
+} {13}
+
+
 finish_test

test/select4.test

@@ -864,4 +864,41 @@ do_execsql_test select4-14.9 {
   SELECT * FROM t14 UNION ALL VALUES(3,2,1),(2,3,1),(1,2,3),(2,1,3);
 } {1 2 3 4 5 6 3 2 1 2 3 1 1 2 3 2 1 3}
 
+# Ticket https://www.sqlite.org/src/tktview/f7f8c97e975978d45  on 2016-04-25
+#
+# The where push-down optimization from 2015-06-02 is suppose to disable
+# on aggregate subqueries.  But if the subquery is a compound where the
+# last SELECT is non-aggregate but some other SELECT is an aggregate, the
+# test is incomplete and the optimization is not properly disabled.
+# 
+# The following test cases verify that the fix works.
+#
+do_execsql_test select4-17.1 {
+  DROP TABLE IF EXISTS t1;
+  CREATE TABLE t1(a int, b int);
+  INSERT INTO t1 VALUES(1,2),(1,18),(2,19);
+  SELECT x, y FROM (
+    SELECT 98 AS x, 99 AS y
+    UNION
+    SELECT a AS x, sum(b) AS y FROM t1 GROUP BY a
+  ) AS w WHERE y>=20
+  ORDER BY +x;
+} {1 20 98 99}
+do_execsql_test select4-17.2 {
+  SELECT x, y FROM (
+    SELECT a AS x, sum(b) AS y FROM t1 GROUP BY a
+    UNION
+    SELECT 98 AS x, 99 AS y
+  ) AS w WHERE y>=20
+  ORDER BY +x;
+} {1 20 98 99}
+do_catchsql_test select4-17.3 {
+  SELECT x, y FROM (
+    SELECT a AS x, sum(b) AS y FROM t1 GROUP BY a LIMIT 3
+    UNION
+    SELECT 98 AS x, 99 AS y
+  ) AS w WHERE y>=20
+  ORDER BY +x;
+} {1 {LIMIT clause should come after UNION not before}}
+
 finish_test

test/whereD.test

@@ -156,7 +156,7 @@ do_searchcount_test 3.4.4 {
 
 do_searchcount_test 3.5.1 {
   SELECT a, b FROM t3 WHERE (a=1 AND b='one') OR rowid=4
-} {1 one 2 two search 2}
+} {1 one 2 two search 1}
 do_searchcount_test 3.5.2 {
   SELECT a, c FROM t3 WHERE (a=1 AND b='one') OR rowid=4
 } {1 i 2 ii search 2}
@@ -271,5 +271,76 @@ do_execsql_test 5.3 {
     c16=1 or c17=1;
 } {1 {} {} {} {} {} {} {} {} {} {} {} {} {} {} 1 {} {}}
 
+#-------------------------------------------------------------------------
+#-------------------------------------------------------------------------
+do_execsql_test 6.1 {
+  CREATE TABLE x1(a, b, c, d, e);
+  CREATE INDEX x1a  ON x1(a);
+  CREATE INDEX x1bc ON x1(b, c);
+  CREATE INDEX x1cd ON x1(c, d);
+
+  INSERT INTO x1 VALUES(1, 2, 3, 4, 'A');
+  INSERT INTO x1 VALUES(5, 6, 7, 8, 'B');
+  INSERT INTO x1 VALUES(9, 10, 11, 12, 'C');
+  INSERT INTO x1 VALUES(13, 14, 15, 16, 'D');
+}
+
+do_searchcount_test 6.2.1 {
+  SELECT e FROM x1 WHERE b=2 OR c=7;
+} {A B search 6}
+do_searchcount_test 6.2.2 {
+  SELECT c FROM x1 WHERE b=2 OR c=7;
+} {3 7 search 4}
+
+do_searchcount_test 6.3.1 {
+  SELECT e FROM x1 WHERE a=1 OR b=10;
+} {A C search 6}
+do_searchcount_test 6.3.2 {
+  SELECT c FROM x1 WHERE a=1 OR b=10;
+} {3 11 search 5}
+do_searchcount_test 6.3.3 {
+  SELECT rowid FROM x1 WHERE a=1 OR b=10;
+} {1 3 search 4}
+
+do_searchcount_test 6.4.1 {
+  SELECT a FROM x1 WHERE b BETWEEN 1 AND 4 OR c BETWEEN 8 AND 12
+} {1 9 search 6}
+do_searchcount_test 6.4.2 {
+  SELECT b, c FROM x1 WHERE b BETWEEN 1 AND 4 OR c BETWEEN 8 AND 12
+} {2 3 10 11 search 5}
+do_searchcount_test 6.4.3 {
+  SELECT rowid, c FROM x1 WHERE b BETWEEN 1 AND 4 OR c BETWEEN 8 AND 12
+} {1 3 3 11 search 4}
+
+db eval {
+  WITH RECURSIVE c(x) AS (VALUES(1000) UNION ALL SELECT x+1 FROM c WHERE x<2000)
+  INSERT INTO x1(rowid,a,b,c,d,e) SELECT x,x,x,x,x,x FROM c;
+}
+
+do_searchcount_test 6.5.1 {
+  SELECT a FROM x1 WHERE rowid = 2 OR c=11
+} {5 9 search 3}
+do_searchcount_test 6.5.2 {
+  SELECT d FROM x1 WHERE rowid = 2 OR c=11
+} {8 12 search 2}
+do_searchcount_test 6.5.3 {
+  SELECT d FROM x1 WHERE c=11 OR rowid = 2
+} {12 8 search 2}
+do_searchcount_test 6.5.4 {
+  SELECT a FROM x1 WHERE c=11 OR rowid = 2 
+} {9 5 search 3}
+
+do_searchcount_test 6.6.1 {
+  SELECT rowid FROM x1 WHERE a=1 OR b=6 OR c=11
+} {1 2 3 search 6}
+do_searchcount_test 6.6.2 {
+  SELECT c FROM x1 WHERE a=1 OR b=6 OR c=11
+} {3 7 11 search 7}
+do_searchcount_test 6.6.3 {
+  SELECT c FROM x1 WHERE c=11 OR a=1 OR b=6 
+} {11 3 7 search 7}
+do_searchcount_test 6.6.4 {
+  SELECT c FROM x1 WHERE b=6 OR c=11 OR a=1
+} {7 11 3 search 7}
 
 finish_test