Run as many Bloom filters as possible before index lookups.

FossilOrigin-Name: 06f6fefd67086896bc49272c6319545ff6c6792f18babe23aced27b60b032119

manifest

@@ -1,5 +1,5 @@
-C Try\sto\srun\sall\sBloom\sfilters\sbefore\sany\sSeeks.\s\sThis\sgives\sa\ssmall\sperformance\ngain\son\sthe\sStar-Schema\sBenchmark.
+C Run\sas\smany\sBloom\sfilters\sas\spossible\sbefore\sindex\slookups.
-D 2021-12-05T00:45:55.528
+D 2021-12-05T20:19:47.744
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -555,7 +555,7 @@ F src/shell.c.in e7ee6517544d075d9f06ee2571567026b89cf9fbeef16a74918019b1cb42576
 F src/sqlite.h.in 5cd209ac7dc4180f0e19292846f40440b8488015849ca0110c70b906b57d68f0
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 8ff2fd2c166150b2e48639f5e506fb44e29f1a3f65031710b9e89d1c126ac839
-F src/sqliteInt.h 4a19ff088cc3bb1467cca94011eaf7e8432476124bbb72c77053d9f1e6b0a6c7
+F src/sqliteInt.h 178eb899c1edc08dcddf37e79dfaa39404a1f5d44a1d512509cd5d41867aa836
 F src/sqliteLimit.h d7323ffea5208c6af2734574bae933ca8ed2ab728083caa117c9738581a31657
 F src/status.c 4b8bc2a6905163a38b739854a35b826c737333fab5b1f8e03fa7eb9a4799c4c1
 F src/table.c 0f141b58a16de7e2fbe81c308379e7279f4c6b50eb08efeec5892794a0ba30d1
@@ -637,9 +637,9 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c ed0398a7adf02c31e34aada42cc86c58f413a7afe5f741a5d373ad087abde028
 F src/wal.h c3aa7825bfa2fe0d85bef2db94655f99870a285778baa36307c0a16da32b226a
 F src/walker.c f890a3298418d7cba3b69b8803594fdc484ea241206a8dfa99db6dd36f8cbb3b
-F src/where.c 3d29b27e345a28f76ecb20b0c789a224e9dc74534363c3ddbc44c283eb4cb708
+F src/where.c b07c5eefecffa1b69b91c366a83c69d01a83f1c900b9d9b1ffb6eb5ab59902a1
-F src/whereInt.h 3c634e184de128d99c2b017f899f2309c77330de54193ff970597e9acdeaff3b
+F src/whereInt.h 5c6601d6d0b7b8936482506d2d835981cc6efcd8e106a829893a27a14cfb10b8
-F src/wherecode.c 48b456c910d552e1edf098071546c523837356ba0e3703d7b8fd9fc819da1c9b
+F src/wherecode.c fa667db48db1077b42731bfd97e9181b39409ffdc7051162ecae6895ca71ad2c
 F src/whereexpr.c 19394cb463003e9cc9305730b1508b8817a22bb7247170d81234b691a7f05b89
 F src/window.c 5d3b397b0c026d0ff5890244ac41359e524c01ae31e78782e1ff418c3e271a9e
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
@@ -1933,7 +1933,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 201b6dd875b0ae2bbc9969b098e88abfc09e37b59e857decd41f2dcbeeb13e01
+P 5be2470f8755ef454f813c880e659bdbf82f2396be9320cf3079cd4ca8e81a19
-R 8ad2d75d69a2ffc06bdf1b52eb7537e1
+R da3cb867f9ab99abba060de93457c8d9
 U drh
-Z 42400fd1219d022ab29b577e6d964b89
+Z d87a509afa829d1cf21b5a6dcadef441

manifest.uuid

@@ -1 +1 @@
-5be2470f8755ef454f813c880e659bdbf82f2396be9320cf3079cd4ca8e81a19
+06f6fefd67086896bc49272c6319545ff6c6792f18babe23aced27b60b032119

src/sqliteInt.h

@@ -1762,6 +1762,7 @@ struct sqlite3 {
 #define SQLITE_OmitOrderBy    0x00040000 /* Omit pointless ORDER BY */
    /* TH3 expects this value  ^^^^^^^^^^ to be 0x40000. Coordinate any change */
 #define SQLITE_BloomFilter    0x00080000 /* Use a Bloom filter on searches */
+#define SQLITE_BloomPulldown  0x00100000 /* Run Bloom filters early */
 #define SQLITE_AllOpts        0xffffffff /* All optimizations */
 
 /*

src/where.c

@@ -966,30 +966,52 @@ end_auto_index_create:
 #endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
 
 /*
-** Create a Bloom filter for the WhereLevel in the parameter.
+** Generate bytecode that will initialize a Bloom filter that is appropriate
+** for pLevel.
+**
+** If there are inner loops within pLevel that have the WHERE_BLOOMFILTER
+** flag set, initialize a Bloomfilter for them as well.  Except don't do
+** this recursive initialization if the SQLITE_BloomPulldown optimization has
+** been turned off.
+**
+** When the Bloom filter is initialized, the WHERE_BLOOMFILTER flag is cleared
+** from the loop, but the regFilter value is set to a register that implements
+** the Bloom filter.  When regFilter is positive, the
+** sqlite3WhereCodeOneLoopStart() will generate code to test the Bloom filter
+** and skip the subsequence B-Tree seek if the Bloom filter indicates that
+** no matching rows exist.
+**
+** This routine may only be called if it has previously been determined that
+** the loop would benefit from a Bloom filter, and the WHERE_BLOOMFILTER bit
+** is set.
 */
-SQLITE_NOINLINE void sqlite3ConstructBloomFilter(
+static SQLITE_NOINLINE void constructBloomFilter(
-  const WhereInfo *pWInfo,    /* The WHERE clause */
+  WhereInfo *pWInfo,    /* The WHERE clause */
+  int iLevel,           /* Index in pWInfo->a[] that is pLevel */
   WhereLevel *pLevel    /* Make a Bloom filter for this FROM term */
 ){
-  int addrTop;
+  int addrOnce;                        /* Address of opening OP_Once */
-  int addrCont;
+  int addrTop;                         /* Address of OP_Rewind */
-  const WhereTerm *pTerm;
+  int addrCont;                        /* Jump here to skip a row */
-  const WhereTerm *pWCEnd;
+  const WhereTerm *pTerm;              /* For looping over WHERE clause terms */
-  Parse *pParse = pWInfo->pParse;
+  const WhereTerm *pWCEnd;             /* Last WHERE clause term */
-  Vdbe *v = pParse->pVdbe;
+  Parse *pParse = pWInfo->pParse;      /* Parsing context */
-  const WhereLoop *pLoop = pLevel->pWLoop;
+  Vdbe *v = pParse->pVdbe;             /* VDBE under construction */
-  int iCur;
+  WhereLoop *pLoop = pLevel->pWLoop;   /* The loop being coded */
-  
+  int iCur;                            /* Cursor for table getting the filter */
 
   assert( pLoop!=0 );
   assert( v!=0 );
-  iCur = pLevel->iTabCur;
+  assert( pLoop->wsFlags & WHERE_BLOOMFILTER );
+
+  addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
+  do{
+    sqlite3WhereExplainBloomFilter(pParse, pWInfo, pLevel);
     addrCont = sqlite3VdbeMakeLabel(pParse);
-  addrTop = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
+    iCur = pLevel->iTabCur;
     pLevel->regFilter = ++pParse->nMem;
     sqlite3VdbeAddOp1(v, OP_FilterInit, pLevel->regFilter);
-  sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
+    addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
     pWCEnd = &pWInfo->sWC.a[pWInfo->sWC.nTerm];
     for(pTerm=pWInfo->sWC.a; pTerm<pWCEnd; pTerm++){
       Expr *pExpr = pTerm->pExpr;
@@ -1017,10 +1039,19 @@ SQLITE_NOINLINE void sqlite3ConstructBloomFilter(
       sqlite3ReleaseTempRange(pParse, r1, n);
     }
     sqlite3VdbeResolveLabel(v, addrCont);
-  sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+3);
+    sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1);
     VdbeCoverage(v);
     sqlite3VdbeJumpHere(v, addrTop);
-  sqlite3VdbeJumpHere(v, addrTop+2);
+    pLoop->wsFlags &= ~WHERE_BLOOMFILTER;
+    if( OptimizationDisabled(pParse->db, SQLITE_BloomPulldown) ) break;
+    while( iLevel < pWInfo->nLevel ){
+      iLevel++;
+      pLevel = &pWInfo->a[iLevel];
+      pLoop = pLevel->pWLoop;
+      if( pLoop && pLoop->wsFlags & WHERE_BLOOMFILTER ) break;
+    }
+  }while( iLevel < pWInfo->nLevel );
+  sqlite3VdbeJumpHere(v, addrOnce);
 }
 
 
@@ -5535,7 +5566,7 @@ WhereInfo *sqlite3WhereBegin(
                   &pTabList->a[pLevel->iFrom], notReady, pLevel);
 #endif
       }else{
-        sqlite3ConstructBloomFilter(pWInfo, pLevel);
+        constructBloomFilter(pWInfo, ii, pLevel);
       }
       if( db->mallocFailed ) goto whereBeginError;
     }

src/whereInt.h

@@ -484,7 +484,6 @@ struct WhereInfo {
 ** where.c:
 */
 Bitmask sqlite3WhereGetMask(WhereMaskSet*,int);
-void sqlite3ConstructBloomFilter(const WhereInfo*, WhereLevel*);
 #ifdef WHERETRACE_ENABLED
 void sqlite3WhereClausePrint(WhereClause *pWC);
 void sqlite3WhereTermPrint(WhereTerm *pTerm, int iTerm);
@@ -507,8 +506,14 @@ int sqlite3WhereExplainOneScan(
   WhereLevel *pLevel,             /* Scan to write OP_Explain opcode for */
   u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */
 );
+int sqlite3WhereExplainBloomFilter(
+  const Parse *pParse,            /* Parse context */
+  const WhereInfo *pWInfo,        /* WHERE clause */
+  const WhereLevel *pLevel        /* Bloom filter on this level */
+);
 #else
 # define sqlite3WhereExplainOneScan(u,v,w,x) 0
+# define sqlite3WhereExplainBloomFilter(u,v,w) 0
 #endif /* SQLITE_OMIT_EXPLAIN */
 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
 void sqlite3WhereAddScanStatus(

src/wherecode.c

@@ -196,9 +196,6 @@ int sqlite3WhereExplainOneScan(
                   pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr);
     }
 #endif
-    if( flags & WHERE_BLOOMFILTER ){
-      sqlite3_str_appendf(&str, " WITH BLOOM FILTER");
-    }
 #ifdef SQLITE_EXPLAIN_ESTIMATED_ROWS
     if( pLoop->nOut>=10 ){
       sqlite3_str_appendf(&str, " (~%llu rows)",
@@ -214,6 +211,52 @@ int sqlite3WhereExplainOneScan(
   }
   return ret;
 }
+
+/*
+** Add a single OP_Explain opcode that describes a Bloom filter.
+**
+** Or if not processing EXPLAIN QUERY PLAN and not in a SQLITE_DEBUG and/or
+** SQLITE_ENABLE_STMT_SCANSTATUS build, then OP_Explain opcodes are not
+** required and this routine is a no-op.
+**
+** If an OP_Explain opcode is added to the VM, its address is returned.
+** Otherwise, if no OP_Explain is coded, zero is returned.
+*/
+int sqlite3WhereExplainBloomFilter(
+  const Parse *pParse,               /* Parse context */
+  const WhereInfo *pWInfo,           /* WHERE clause */
+  const WhereLevel *pLevel           /* Bloom filter on this level */
+){
+  int ret = 0;
+#if !defined(SQLITE_DEBUG) && !defined(SQLITE_ENABLE_STMT_SCANSTATUS)
+  if( sqlite3ParseToplevel(pParse)->explain==2 )
+#endif
+  {
+    SrcItem *pItem = &pWInfo->pTabList->a[pLevel->iFrom];
+    Vdbe *v = pParse->pVdbe;      /* VM being constructed */
+    sqlite3 *db = pParse->db;     /* Database handle */
+    char *zMsg;                   /* Text to add to EQP output */
+    int i;                        /* Loop counter */
+    WhereLoop *pLoop;             /* The where loop */
+    StrAccum str;                 /* EQP output string */
+    char zBuf[100];               /* Initial space for EQP output string */
+
+    sqlite3StrAccumInit(&str, db, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
+    str.printfFlags = SQLITE_PRINTF_INTERNAL;
+    sqlite3_str_appendf(&str, "BLOOM FILTER ON %S(", pItem);
+    pLoop = pLevel->pWLoop;
+    for(i=pLoop->nSkip; i<pLoop->u.btree.nEq; i++){
+      const char *z = pItem->pTab->aCol[i].zCnName;
+      if( i>pLoop->nSkip ) sqlite3_str_append(&str, " AND ", 5);
+      sqlite3_str_appendf(&str, "%s=?", z);
+    }
+    sqlite3_str_append(&str, ")", 1);
+    zMsg = sqlite3StrAccumFinish(&str);
+    ret = sqlite3VdbeAddOp4(v, OP_Explain, sqlite3VdbeCurrentAddr(v),
+                            pParse->addrExplain, 0, zMsg,P4_DYNAMIC);
+  }
+  return ret;
+}
 #endif /* SQLITE_OMIT_EXPLAIN */
 
 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
@@ -1304,14 +1347,20 @@ static void whereApplyPartialIndexConstraints(
   }
 }
 
-#if 1
 /*
-** An OP_Filter has just been generated, but the corresponding
+** This routine is called right after An OP_Filter has been generated and
-** index search has not yet been performed.  This routine
+** before the corresponding index search has been performed.  This routine
-** checks to see if there are additional WHERE_BLOOMFILTER in
+** checks to see if there are additional Bloom filters in inner loops that
-** inner loops that can be evaluated right away, and if there are,
+** can be checked prior to doing the index lookup.  If there are available
-** it evaluates those filters as well, and removes the WHERE_BLOOMFILTER
+** inner-loop Bloom filters, then evaluate those filters now, before the
-** tag.
+** index lookup.  The idea is that a Bloom filter check is way faster than
+** an index lookup, and the Bloom filter might return false, meaning that
+** the index lookup can be skipped.
+**
+** We know that an inner loop uses a Bloom filter because it has the
+** WhereLevel.regFilter set.  If an inner-loop Bloom filter is checked,
+** then clear the WhereLoeve.regFilter value to prevent the Bloom filter
+** from being checked a second time when the inner loop is evaluated.
 */
 static SQLITE_NOINLINE void filterPullDown(
   Parse *pParse,       /* Parsing context */
@@ -1323,9 +1372,8 @@ static SQLITE_NOINLINE void filterPullDown(
   while( ++iLevel < pWInfo->nLevel ){
     WhereLevel *pLevel = &pWInfo->a[iLevel];
     WhereLoop *pLoop = pLevel->pWLoop;
-    if( (pLoop->wsFlags & WHERE_BLOOMFILTER)==0 ) continue;
+    if( pLevel->regFilter==0 ) continue;
     if( pLoop->prereq & notReady ) continue;
-    sqlite3ConstructBloomFilter(pWInfo, &pWInfo->a[iLevel]);
     if( pLoop->wsFlags & WHERE_IPK ){
       WhereTerm *pTerm = pLoop->aLTerm[0];
       int r1, regRowid;
@@ -1351,12 +1399,9 @@ static SQLITE_NOINLINE void filterPullDown(
                            addrNxt, r1, nEq);
       VdbeCoverage(pParse->pVdbe);
     }
-    pLoop->wsFlags &= ~WHERE_BLOOMFILTER;
+    pLevel->regFilter = 0;
   }
 }
-#else
-#define filterPullDown(A,B,C,D,E)
-#endif
 
 /*
 ** Generate code for the start of the iLevel-th loop in the WHERE clause