table.lo threads.lo tokenize.lo trigger.lo \
update.lo util.lo vacuum.lo \
vdbe.lo vdbeapi.lo vdbeaux.lo vdbeblob.lo vdbemem.lo vdbesort.lo \
- vdbetrace.lo wal.lo walker.lo where.lo utf.lo vtab.lo
+ vdbetrace.lo wal.lo walker.lo where.lo wherecode.lo utf.lo vtab.lo
# Object files for the amalgamation.
#
$(TOP)/src/wal.h \
$(TOP)/src/walker.c \
$(TOP)/src/where.c \
+ $(TOP)/src/wherecode.c \
$(TOP)/src/whereInt.h
# Source code for extensions
$(TOP)/src/vdbemem.c \
$(TOP)/src/vdbetrace.c \
$(TOP)/src/where.c \
+ $(TOP)/src/wherecode.c \
parse.c \
$(TOP)/ext/fts3/fts3.c \
$(TOP)/ext/fts3/fts3_aux.c \
where.lo: $(TOP)/src/where.c $(HDR)
$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/where.c
+wherecode.lo: $(TOP)/src/wherecode.c $(HDR)
+ $(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/wherecode.c
+
tclsqlite.lo: $(TOP)/src/tclsqlite.c $(HDR)
$(LTCOMPILE) -DUSE_TCL_STUBS=1 -c $(TOP)/src/tclsqlite.c
table.lo threads.lo tokenize.lo trigger.lo \
update.lo util.lo vacuum.lo \
vdbeapi.lo vdbeaux.lo vdbeblob.lo vdbemem.lo vdbesort.lo \
- vdbetrace.lo wal.lo walker.lo where.lo utf.lo vtab.lo
+ vdbetrace.lo wal.lo walker.lo where.lo wherecode.lo utf.lo vtab.lo
# Object files for the amalgamation.
#
$(TOP)\src\wal.h \
$(TOP)\src\walker.c \
$(TOP)\src\where.c \
+ $(TOP)\src\wherecode.c \
$(TOP)\src\whereInt.h
# Source code for extensions
$(TOP)\src\vdbesort.c \
$(TOP)\src\vdbetrace.c \
$(TOP)\src\where.c \
+ $(TOP)\src\wherecode.c \
parse.c \
$(TOP)\ext\fts3\fts3.c \
$(TOP)\ext\fts3\fts3_aux.c \
where.lo: $(TOP)\src\where.c $(HDR)
$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\where.c
+wherecode.lo: $(TOP)\src\wherecode.c $(HDR)
+ $(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\wherecode.c
+
tclsqlite.lo: $(TOP)\src\tclsqlite.c $(HDR)
$(LTCOMPILE) $(NO_WARN) -DUSE_TCL_STUBS=1 -DBUILD_sqlite -I$(TCLINCDIR) -c $(TOP)\src\tclsqlite.c
table.o threads.o tokenize.o trigger.o \
update.o userauth.o util.o vacuum.o \
vdbeapi.o vdbeaux.o vdbeblob.o vdbemem.o vdbesort.o \
- vdbetrace.o wal.o walker.o where.o utf.o vtab.o
+ vdbetrace.o wal.o walker.o where.o wherecode.o utf.o vtab.o
$(TOP)/src/wal.h \
$(TOP)/src/walker.c \
$(TOP)/src/where.c \
+ $(TOP)/src/wherecode.c \
$(TOP)/src/whereInt.h
# Source code for extensions
$(TOP)/src/vdbe.c \
$(TOP)/src/vdbemem.c \
$(TOP)/src/where.c \
+ $(TOP)/src/wherecode.c \
parse.c \
$(TOP)/ext/fts3/fts3.c \
$(TOP)/ext/fts3/fts3_aux.c \
-C Code\ssimplifications\sin\sselect.c\sand\swhere.c.
-D 2015-06-06T18:30:17.822
+C Split\sout\sthe\sbulk\sof\sthe\sactual\sVDBE\scode\sgeneration\slogic\sfrom\swhere.c\ninto\sa\snew\sfile,\sleaving\sbehind\sthe\sanalysis\slogic.\s\sThis\smakes\sthe\soriginal\nwhere.c\ssmaller\sand\shopefully\seasier\sto\sedit.
+D 2015-06-06T20:12:09.183
F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
-F Makefile.in 994bab32a3a69e0c35bd148b65cde49879772964
+F Makefile.in 64136f59edd49b389b5c5d24388e204929b807e5
F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
-F Makefile.msc d37d2c2323df3acae6e24c71a478889421c17264
+F Makefile.msc e2f1f95dc4a0af0b9ac3c2ee66878700b71ad93f
F Makefile.vxworks e1b65dea203f054e71653415bd8f96dcaed47858
F README.md 8ecc12493ff9f820cdea6520a9016001cb2e59b7
F VERSION ce0ae95abd7121c534f6917c1c8f2b70d9acd4db
F install-sh 9d4de14ab9fb0facae2f48780b874848cbf2f895 x
F ltmain.sh 3ff0879076df340d2e23ae905484d8c15d5fdea8
F magic.txt 8273bf49ba3b0c8559cb2774495390c31fd61c60
-F main.mk 8d418497da6a152a59b00d64ae3d66f3c665974c
+F main.mk b9e0c806c04739b20f281680f8771bc2e20acd54
F mkopcodec.awk c2ff431854d702cdd2d779c9c0d1f58fa16fa4ea
F mkopcodeh.awk d5e22023b5238985bb54a72d33e0ac71fe4f8a32
F mkso.sh fd21c06b063bb16a5d25deea1752c2da6ac3ed83
F src/wal.c ce2cb2d06faab54d1bce3e739bec79e063dd9113
F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4
F src/walker.c c253b95b4ee44b21c406e2a1052636c31ea27804
-F src/where.c 5cc416ad6d8b6d2027735fcf7c5a6165bb745636
-F src/whereInt.h a6f5a762bc1b4b1c76e1cea79976b437ac35a435
+F src/where.c c9d804dcf02388207096e4da19487d9a2a7a9a67
+F src/whereInt.h 40e1d060b6aa02edbb7b8a1f3dfc0cc4ff140881
+F src/wherecode.c 0669481cabaf5caf934b6bb825df15bc57f60d40
F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
F test/affinity2.test a6d901b436328bd67a79b41bb0ac2663918fe3bd
F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
F tool/mkpragmatab.tcl 40c287d3f929ece67da6e9e7c49885789960accf
F tool/mkspeedsql.tcl a1a334d288f7adfe6e996f2e712becf076745c97
F tool/mksqlite3c-noext.tcl 69bae8ce4aa52d2ff82d4a8a856bf283ec035b2e
-F tool/mksqlite3c.tcl fdeab4c1eed90b7ab741ec12a7bc5c2fb60188bd
+F tool/mksqlite3c.tcl 9f60238b2273048a4089077a43716d3b33a67c51
F tool/mksqlite3h.tcl 44730d586c9031638cdd2eb443b801c0d2dbd9f8
F tool/mksqlite3internalh.tcl eb994013e833359137eb53a55acdad0b5ae1049b
F tool/mkvsix.tcl 3b58b9398f91c7dbf18d49eb87cefeee9efdbce1
F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P f4c90d06bb941453d8110680c7b279e471e8f034
-R 042f84cf941d82ab55744b287e51eff7
+P 4f20ac90bce8bd7ba43ef59af5cc4ef7aa282fe8
+R f7b66d3e1070ad2d563a494aba699c70
U drh
-Z f6bc4d318934fdab6d55b7066c6ff342
+Z 85351aea272e066665037522f98406f9
-4f20ac90bce8bd7ba43ef59af5cc4ef7aa282fe8
\ No newline at end of file
+faa0e420e93a2bc1c84df9eb9fef4748d29ce339
\ No newline at end of file
#include "sqliteInt.h"
#include "whereInt.h"
+/* Forward declaration of methods */
+static int whereLoopResize(sqlite3*, WhereLoop*, int);
+
+/* Test variable that can be set to enable WHERE tracing */
+#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
+/***/ int sqlite3WhereTrace = 0;
+#endif
+
+
/*
** Return the estimated number of output rows from a WHERE clause
*/
** Return the bitmask for the given cursor number. Return 0 if
** iCursor is not in the set.
*/
-static Bitmask getMask(WhereMaskSet *pMaskSet, int iCursor){
+Bitmask sqlite3WhereGetMask(WhereMaskSet *pMaskSet, int iCursor){
int i;
assert( pMaskSet->n<=(int)sizeof(Bitmask)*8 );
for(i=0; i<pMaskSet->n; i++){
Bitmask mask = 0;
if( p==0 ) return 0;
if( p->op==TK_COLUMN ){
- mask = getMask(pMaskSet, p->iTable);
+ mask = sqlite3WhereGetMask(pMaskSet, p->iTable);
return mask;
}
mask = exprTableUsage(pMaskSet, p->pRight);
** the form "X <op> <const-expr>" exist. If no terms with a constant RHS
** exist, try to return a term that does not use WO_EQUIV.
*/
-static WhereTerm *findTerm(
+WhereTerm *sqlite3WhereFindTerm(
WhereClause *pWC, /* The WHERE clause to be searched */
int iCur, /* Cursor number of LHS */
int iColumn, /* Column number of LHS */
for(j=0, pAndTerm=pAndWC->a; j<pAndWC->nTerm; j++, pAndTerm++){
assert( pAndTerm->pExpr );
if( allowedOp(pAndTerm->pExpr->op) ){
- b |= getMask(&pWInfo->sMaskSet, pAndTerm->leftCursor);
+ b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pAndTerm->leftCursor);
}
}
}
** corresponding TERM_VIRTUAL term */
}else{
Bitmask b;
- b = getMask(&pWInfo->sMaskSet, pOrTerm->leftCursor);
+ b = sqlite3WhereGetMask(&pWInfo->sMaskSet, pOrTerm->leftCursor);
if( pOrTerm->wtFlags & TERM_VIRTUAL ){
WhereTerm *pOther = &pOrWc->a[pOrTerm->iParent];
- b |= getMask(&pWInfo->sMaskSet, pOther->leftCursor);
+ b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pOther->leftCursor);
}
indexable &= b;
if( (pOrTerm->eOperator & WO_EQ)==0 ){
assert( j==1 );
continue;
}
- if( (chngToIN & getMask(&pWInfo->sMaskSet, pOrTerm->leftCursor))==0 ){
+ if( (chngToIN & sqlite3WhereGetMask(&pWInfo->sMaskSet, pOrTerm->leftCursor))==0 ){
/* This term must be of the form t1.a==t2.b where t2 is in the
** chngToIN set but t1 is not. This term will be either preceded
** or follwed by an inverted copy (t2.b==t1.a). Skip this term
** on the second iteration */
assert( j==1 );
assert( IsPowerOfTwo(chngToIN) );
- assert( chngToIN==getMask(&pWInfo->sMaskSet, iCursor) );
+ assert( chngToIN==sqlite3WhereGetMask(&pWInfo->sMaskSet, iCursor) );
break;
}
testcase( j==1 );
}
prereqAll = exprTableUsage(pMaskSet, pExpr);
if( ExprHasProperty(pExpr, EP_FromJoin) ){
- Bitmask x = getMask(pMaskSet, pExpr->iRightJoinTable);
+ Bitmask x = sqlite3WhereGetMask(pMaskSet, pExpr->iRightJoinTable);
prereqAll |= x;
extraRight = x-1; /* ON clause terms may not be used with an index
** on left table of a LEFT JOIN. Ticket #3015 */
if( !IsUniqueIndex(pIdx) ) continue;
for(i=0; i<pIdx->nKeyCol; i++){
i16 iCol = pIdx->aiColumn[i];
- if( 0==findTerm(pWC, iBase, iCol, ~(Bitmask)0, WO_EQ, pIdx) ){
+ if( 0==sqlite3WhereFindTerm(pWC, iBase, iCol, ~(Bitmask)0, WO_EQ, pIdx) ){
int iIdxCol = findIndexCol(pParse, pDistinct, iBase, pIdx, i);
if( iIdxCol<0 || pTab->aCol[iCol].notNull==0 ){
break;
}
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
-/*
-** Disable a term in the WHERE clause. Except, do not disable the term
-** if it controls a LEFT OUTER JOIN and it did not originate in the ON
-** or USING clause of that join.
-**
-** Consider the term t2.z='ok' in the following queries:
-**
-** (1) SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x WHERE t2.z='ok'
-** (2) SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x AND t2.z='ok'
-** (3) SELECT * FROM t1, t2 WHERE t1.a=t2.x AND t2.z='ok'
-**
-** The t2.z='ok' is disabled in the in (2) because it originates
-** in the ON clause. The term is disabled in (3) because it is not part
-** of a LEFT OUTER JOIN. In (1), the term is not disabled.
-**
-** Disabling a term causes that term to not be tested in the inner loop
-** of the join. Disabling is an optimization. When terms are satisfied
-** by indices, we disable them to prevent redundant tests in the inner
-** loop. We would get the correct results if nothing were ever disabled,
-** but joins might run a little slower. The trick is to disable as much
-** as we can without disabling too much. If we disabled in (1), we'd get
-** the wrong answer. See ticket #813.
-**
-** If all the children of a term are disabled, then that term is also
-** automatically disabled. In this way, terms get disabled if derived
-** virtual terms are tested first. For example:
-**
-** x GLOB 'abc*' AND x>='abc' AND x<'acd'
-** \___________/ \______/ \_____/
-** parent child1 child2
-**
-** Only the parent term was in the original WHERE clause. The child1
-** and child2 terms were added by the LIKE optimization. If both of
-** the virtual child terms are valid, then testing of the parent can be
-** skipped.
-**
-** Usually the parent term is marked as TERM_CODED. But if the parent
-** term was originally TERM_LIKE, then the parent gets TERM_LIKECOND instead.
-** The TERM_LIKECOND marking indicates that the term should be coded inside
-** a conditional such that is only evaluated on the second pass of a
-** LIKE-optimization loop, when scanning BLOBs instead of strings.
-*/
-static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
- int nLoop = 0;
- while( pTerm
- && (pTerm->wtFlags & TERM_CODED)==0
- && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
- && (pLevel->notReady & pTerm->prereqAll)==0
- ){
- if( nLoop && (pTerm->wtFlags & TERM_LIKE)!=0 ){
- pTerm->wtFlags |= TERM_LIKECOND;
- }else{
- pTerm->wtFlags |= TERM_CODED;
- }
- if( pTerm->iParent<0 ) break;
- pTerm = &pTerm->pWC->a[pTerm->iParent];
- pTerm->nChild--;
- if( pTerm->nChild!=0 ) break;
- nLoop++;
- }
-}
-
-/*
-** Code an OP_Affinity opcode to apply the column affinity string zAff
-** to the n registers starting at base.
-**
-** As an optimization, SQLITE_AFF_BLOB entries (which are no-ops) at the
-** beginning and end of zAff are ignored. If all entries in zAff are
-** SQLITE_AFF_BLOB, then no code gets generated.
-**
-** This routine makes its own copy of zAff so that the caller is free
-** to modify zAff after this routine returns.
-*/
-static void codeApplyAffinity(Parse *pParse, int base, int n, char *zAff){
- Vdbe *v = pParse->pVdbe;
- if( zAff==0 ){
- assert( pParse->db->mallocFailed );
- return;
- }
- assert( v!=0 );
-
- /* Adjust base and n to skip over SQLITE_AFF_BLOB entries at the beginning
- ** and end of the affinity string.
- */
- while( n>0 && zAff[0]==SQLITE_AFF_BLOB ){
- n--;
- base++;
- zAff++;
- }
- while( n>1 && zAff[n-1]==SQLITE_AFF_BLOB ){
- n--;
- }
-
- /* Code the OP_Affinity opcode if there is anything left to do. */
- if( n>0 ){
- sqlite3VdbeAddOp2(v, OP_Affinity, base, n);
- sqlite3VdbeChangeP4(v, -1, zAff, n);
- sqlite3ExprCacheAffinityChange(pParse, base, n);
- }
-}
-
-
-/*
-** Generate code for a single equality term of the WHERE clause. An equality
-** term can be either X=expr or X IN (...). pTerm is the term to be
-** coded.
-**
-** The current value for the constraint is left in register iReg.
-**
-** For a constraint of the form X=expr, the expression is evaluated and its
-** result is left on the stack. For constraints of the form X IN (...)
-** this routine sets up a loop that will iterate over all values of X.
-*/
-static int codeEqualityTerm(
- Parse *pParse, /* The parsing context */
- WhereTerm *pTerm, /* The term of the WHERE clause to be coded */
- WhereLevel *pLevel, /* The level of the FROM clause we are working on */
- int iEq, /* Index of the equality term within this level */
- int bRev, /* True for reverse-order IN operations */
- int iTarget /* Attempt to leave results in this register */
-){
- Expr *pX = pTerm->pExpr;
- Vdbe *v = pParse->pVdbe;
- int iReg; /* Register holding results */
-
- assert( iTarget>0 );
- if( pX->op==TK_EQ || pX->op==TK_IS ){
- iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);
- }else if( pX->op==TK_ISNULL ){
- iReg = iTarget;
- sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
-#ifndef SQLITE_OMIT_SUBQUERY
- }else{
- int eType;
- int iTab;
- struct InLoop *pIn;
- WhereLoop *pLoop = pLevel->pWLoop;
-
- if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0
- && pLoop->u.btree.pIndex!=0
- && pLoop->u.btree.pIndex->aSortOrder[iEq]
- ){
- testcase( iEq==0 );
- testcase( bRev );
- bRev = !bRev;
- }
- assert( pX->op==TK_IN );
- iReg = iTarget;
- eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0);
- if( eType==IN_INDEX_INDEX_DESC ){
- testcase( bRev );
- bRev = !bRev;
- }
- iTab = pX->iTable;
- sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);
- VdbeCoverageIf(v, bRev);
- VdbeCoverageIf(v, !bRev);
- assert( (pLoop->wsFlags & WHERE_MULTI_OR)==0 );
- pLoop->wsFlags |= WHERE_IN_ABLE;
- if( pLevel->u.in.nIn==0 ){
- pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
- }
- pLevel->u.in.nIn++;
- pLevel->u.in.aInLoop =
- sqlite3DbReallocOrFree(pParse->db, pLevel->u.in.aInLoop,
- sizeof(pLevel->u.in.aInLoop[0])*pLevel->u.in.nIn);
- pIn = pLevel->u.in.aInLoop;
- if( pIn ){
- pIn += pLevel->u.in.nIn - 1;
- pIn->iCur = iTab;
- if( eType==IN_INDEX_ROWID ){
- pIn->addrInTop = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iReg);
- }else{
- pIn->addrInTop = sqlite3VdbeAddOp3(v, OP_Column, iTab, 0, iReg);
- }
- pIn->eEndLoopOp = bRev ? OP_PrevIfOpen : OP_NextIfOpen;
- sqlite3VdbeAddOp1(v, OP_IsNull, iReg); VdbeCoverage(v);
- }else{
- pLevel->u.in.nIn = 0;
- }
-#endif
- }
- disableTerm(pLevel, pTerm);
- return iReg;
-}
-
-/*
-** Generate code that will evaluate all == and IN constraints for an
-** index scan.
-**
-** For example, consider table t1(a,b,c,d,e,f) with index i1(a,b,c).
-** Suppose the WHERE clause is this: a==5 AND b IN (1,2,3) AND c>5 AND c<10
-** The index has as many as three equality constraints, but in this
-** example, the third "c" value is an inequality. So only two
-** constraints are coded. This routine will generate code to evaluate
-** a==5 and b IN (1,2,3). The current values for a and b will be stored
-** in consecutive registers and the index of the first register is returned.
-**
-** In the example above nEq==2. But this subroutine works for any value
-** of nEq including 0. If nEq==0, this routine is nearly a no-op.
-** The only thing it does is allocate the pLevel->iMem memory cell and
-** compute the affinity string.
-**
-** The nExtraReg parameter is 0 or 1. It is 0 if all WHERE clause constraints
-** are == or IN and are covered by the nEq. nExtraReg is 1 if there is
-** an inequality constraint (such as the "c>=5 AND c<10" in the example) that
-** occurs after the nEq quality constraints.
-**
-** This routine allocates a range of nEq+nExtraReg memory cells and returns
-** the index of the first memory cell in that range. The code that
-** calls this routine will use that memory range to store keys for
-** start and termination conditions of the loop.
-** key value of the loop. If one or more IN operators appear, then
-** this routine allocates an additional nEq memory cells for internal
-** use.
-**
-** Before returning, *pzAff is set to point to a buffer containing a
-** copy of the column affinity string of the index allocated using
-** sqlite3DbMalloc(). Except, entries in the copy of the string associated
-** with equality constraints that use BLOB or NONE affinity are set to
-** SQLITE_AFF_BLOB. This is to deal with SQL such as the following:
-**
-** CREATE TABLE t1(a TEXT PRIMARY KEY, b);
-** SELECT ... FROM t1 AS t2, t1 WHERE t1.a = t2.b;
-**
-** In the example above, the index on t1(a) has TEXT affinity. But since
-** the right hand side of the equality constraint (t2.b) has BLOB/NONE affinity,
-** no conversion should be attempted before using a t2.b value as part of
-** a key to search the index. Hence the first byte in the returned affinity
-** string in this example would be set to SQLITE_AFF_BLOB.
-*/
-static int codeAllEqualityTerms(
- Parse *pParse, /* Parsing context */
- WhereLevel *pLevel, /* Which nested loop of the FROM we are coding */
- int bRev, /* Reverse the order of IN operators */
- int nExtraReg, /* Number of extra registers to allocate */
- char **pzAff /* OUT: Set to point to affinity string */
-){
- u16 nEq; /* The number of == or IN constraints to code */
- u16 nSkip; /* Number of left-most columns to skip */
- Vdbe *v = pParse->pVdbe; /* The vm under construction */
- Index *pIdx; /* The index being used for this loop */
- WhereTerm *pTerm; /* A single constraint term */
- WhereLoop *pLoop; /* The WhereLoop object */
- int j; /* Loop counter */
- int regBase; /* Base register */
- int nReg; /* Number of registers to allocate */
- char *zAff; /* Affinity string to return */
-
- /* This module is only called on query plans that use an index. */
- pLoop = pLevel->pWLoop;
- assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );
- nEq = pLoop->u.btree.nEq;
- nSkip = pLoop->nSkip;
- pIdx = pLoop->u.btree.pIndex;
- assert( pIdx!=0 );
-
- /* Figure out how many memory cells we will need then allocate them.
- */
- regBase = pParse->nMem + 1;
- nReg = pLoop->u.btree.nEq + nExtraReg;
- pParse->nMem += nReg;
-
- zAff = sqlite3DbStrDup(pParse->db, sqlite3IndexAffinityStr(v, pIdx));
- if( !zAff ){
- pParse->db->mallocFailed = 1;
- }
-
- if( nSkip ){
- int iIdxCur = pLevel->iIdxCur;
- sqlite3VdbeAddOp1(v, (bRev?OP_Last:OP_Rewind), iIdxCur);
- VdbeCoverageIf(v, bRev==0);
- VdbeCoverageIf(v, bRev!=0);
- VdbeComment((v, "begin skip-scan on %s", pIdx->zName));
- j = sqlite3VdbeAddOp0(v, OP_Goto);
- pLevel->addrSkip = sqlite3VdbeAddOp4Int(v, (bRev?OP_SeekLT:OP_SeekGT),
- iIdxCur, 0, regBase, nSkip);
- VdbeCoverageIf(v, bRev==0);
- VdbeCoverageIf(v, bRev!=0);
- sqlite3VdbeJumpHere(v, j);
- for(j=0; j<nSkip; j++){
- sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, j, regBase+j);
- assert( pIdx->aiColumn[j]>=0 );
- VdbeComment((v, "%s", pIdx->pTable->aCol[pIdx->aiColumn[j]].zName));
- }
- }
-
- /* Evaluate the equality constraints
- */
- assert( zAff==0 || (int)strlen(zAff)>=nEq );
- for(j=nSkip; j<nEq; j++){
- int r1;
- pTerm = pLoop->aLTerm[j];
- assert( pTerm!=0 );
- /* The following testcase is true for indices with redundant columns.
- ** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */
- testcase( (pTerm->wtFlags & TERM_CODED)!=0 );
- testcase( pTerm->wtFlags & TERM_VIRTUAL );
- r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, regBase+j);
- if( r1!=regBase+j ){
- if( nReg==1 ){
- sqlite3ReleaseTempReg(pParse, regBase);
- regBase = r1;
- }else{
- sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
- }
- }
- testcase( pTerm->eOperator & WO_ISNULL );
- testcase( pTerm->eOperator & WO_IN );
- if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){
- Expr *pRight = pTerm->pExpr->pRight;
- if( (pTerm->wtFlags & TERM_IS)==0 && sqlite3ExprCanBeNull(pRight) ){
- sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->addrBrk);
- VdbeCoverage(v);
- }
- if( zAff ){
- if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_BLOB ){
- zAff[j] = SQLITE_AFF_BLOB;
- }
- if( sqlite3ExprNeedsNoAffinityChange(pRight, zAff[j]) ){
- zAff[j] = SQLITE_AFF_BLOB;
- }
- }
- }
- }
- *pzAff = zAff;
- return regBase;
-}
-
-#ifndef SQLITE_OMIT_EXPLAIN
-/*
-** This routine is a helper for explainIndexRange() below
-**
-** pStr holds the text of an expression that we are building up one term
-** at a time. This routine adds a new term to the end of the expression.
-** Terms are separated by AND so add the "AND" text for second and subsequent
-** terms only.
-*/
-static void explainAppendTerm(
- StrAccum *pStr, /* The text expression being built */
- int iTerm, /* Index of this term. First is zero */
- const char *zColumn, /* Name of the column */
- const char *zOp /* Name of the operator */
-){
- if( iTerm ) sqlite3StrAccumAppend(pStr, " AND ", 5);
- sqlite3StrAccumAppendAll(pStr, zColumn);
- sqlite3StrAccumAppend(pStr, zOp, 1);
- sqlite3StrAccumAppend(pStr, "?", 1);
-}
-
-/*
-** Argument pLevel describes a strategy for scanning table pTab. This
-** function appends text to pStr that describes the subset of table
-** rows scanned by the strategy in the form of an SQL expression.
-**
-** For example, if the query:
-**
-** SELECT * FROM t1 WHERE a=1 AND b>2;
-**
-** is run and there is an index on (a, b), then this function returns a
-** string similar to:
-**
-** "a=? AND b>?"
-*/
-static void explainIndexRange(StrAccum *pStr, WhereLoop *pLoop, Table *pTab){
- Index *pIndex = pLoop->u.btree.pIndex;
- u16 nEq = pLoop->u.btree.nEq;
- u16 nSkip = pLoop->nSkip;
- int i, j;
- Column *aCol = pTab->aCol;
- i16 *aiColumn = pIndex->aiColumn;
-
- if( nEq==0 && (pLoop->wsFlags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ) return;
- sqlite3StrAccumAppend(pStr, " (", 2);
- for(i=0; i<nEq; i++){
- char *z = aiColumn[i] < 0 ? "rowid" : aCol[aiColumn[i]].zName;
- if( i>=nSkip ){
- explainAppendTerm(pStr, i, z, "=");
- }else{
- if( i ) sqlite3StrAccumAppend(pStr, " AND ", 5);
- sqlite3XPrintf(pStr, 0, "ANY(%s)", z);
- }
- }
-
- j = i;
- if( pLoop->wsFlags&WHERE_BTM_LIMIT ){
- char *z = aiColumn[j] < 0 ? "rowid" : aCol[aiColumn[j]].zName;
- explainAppendTerm(pStr, i++, z, ">");
- }
- if( pLoop->wsFlags&WHERE_TOP_LIMIT ){
- char *z = aiColumn[j] < 0 ? "rowid" : aCol[aiColumn[j]].zName;
- explainAppendTerm(pStr, i, z, "<");
- }
- sqlite3StrAccumAppend(pStr, ")", 1);
-}
-
-/*
-** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN
-** command, or if either SQLITE_DEBUG or SQLITE_ENABLE_STMT_SCANSTATUS was
-** defined at compile-time. If it is not a no-op, a single OP_Explain opcode
-** is added to the output to describe the table scan strategy in pLevel.
-**
-** If an OP_Explain opcode is added to the VM, its address is returned.
-** Otherwise, if no OP_Explain is coded, zero is returned.
-*/
-static int explainOneScan(
- Parse *pParse, /* Parse context */
- SrcList *pTabList, /* Table list this loop refers to */
- WhereLevel *pLevel, /* Scan to write OP_Explain opcode for */
- int iLevel, /* Value for "level" column of output */
- int iFrom, /* Value for "from" column of output */
- u16 wctrlFlags /* Flags passed to sqlite3WhereBegin() */
-){
- int ret = 0;
-#if !defined(SQLITE_DEBUG) && !defined(SQLITE_ENABLE_STMT_SCANSTATUS)
- if( pParse->explain==2 )
-#endif
- {
- struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
- Vdbe *v = pParse->pVdbe; /* VM being constructed */
- sqlite3 *db = pParse->db; /* Database handle */
- int iId = pParse->iSelectId; /* Select id (left-most output column) */
- int isSearch; /* True for a SEARCH. False for SCAN. */
- WhereLoop *pLoop; /* The controlling WhereLoop object */
- u32 flags; /* Flags that describe this loop */
- char *zMsg; /* Text to add to EQP output */
- StrAccum str; /* EQP output string */
- char zBuf[100]; /* Initial space for EQP output string */
-
- pLoop = pLevel->pWLoop;
- flags = pLoop->wsFlags;
- if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_ONETABLE_ONLY) ) return 0;
-
- isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
- || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
- || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));
-
- sqlite3StrAccumInit(&str, db, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
- sqlite3StrAccumAppendAll(&str, isSearch ? "SEARCH" : "SCAN");
- if( pItem->pSelect ){
- sqlite3XPrintf(&str, 0, " SUBQUERY %d", pItem->iSelectId);
- }else{
- sqlite3XPrintf(&str, 0, " TABLE %s", pItem->zName);
- }
-
- if( pItem->zAlias ){
- sqlite3XPrintf(&str, 0, " AS %s", pItem->zAlias);
- }
- if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 ){
- const char *zFmt = 0;
- Index *pIdx;
-
- assert( pLoop->u.btree.pIndex!=0 );
- pIdx = pLoop->u.btree.pIndex;
- assert( !(flags&WHERE_AUTO_INDEX) || (flags&WHERE_IDX_ONLY) );
- if( !HasRowid(pItem->pTab) && IsPrimaryKeyIndex(pIdx) ){
- if( isSearch ){
- zFmt = "PRIMARY KEY";
- }
- }else if( flags & WHERE_PARTIALIDX ){
- zFmt = "AUTOMATIC PARTIAL COVERING INDEX";
- }else if( flags & WHERE_AUTO_INDEX ){
- zFmt = "AUTOMATIC COVERING INDEX";
- }else if( flags & WHERE_IDX_ONLY ){
- zFmt = "COVERING INDEX %s";
- }else{
- zFmt = "INDEX %s";
- }
- if( zFmt ){
- sqlite3StrAccumAppend(&str, " USING ", 7);
- sqlite3XPrintf(&str, 0, zFmt, pIdx->zName);
- explainIndexRange(&str, pLoop, pItem->pTab);
- }
- }else if( (flags & WHERE_IPK)!=0 && (flags & WHERE_CONSTRAINT)!=0 ){
- const char *zRange;
- if( flags&(WHERE_COLUMN_EQ|WHERE_COLUMN_IN) ){
- zRange = "(rowid=?)";
- }else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){
- zRange = "(rowid>? AND rowid<?)";
- }else if( flags&WHERE_BTM_LIMIT ){
- zRange = "(rowid>?)";
- }else{
- assert( flags&WHERE_TOP_LIMIT);
- zRange = "(rowid<?)";
- }
- sqlite3StrAccumAppendAll(&str, " USING INTEGER PRIMARY KEY ");
- sqlite3StrAccumAppendAll(&str, zRange);
- }
-#ifndef SQLITE_OMIT_VIRTUALTABLE
- else if( (flags & WHERE_VIRTUALTABLE)!=0 ){
- sqlite3XPrintf(&str, 0, " VIRTUAL TABLE INDEX %d:%s",
- pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr);
- }
-#endif
-#ifdef SQLITE_EXPLAIN_ESTIMATED_ROWS
- if( pLoop->nOut>=10 ){
- sqlite3XPrintf(&str, 0, " (~%llu rows)", sqlite3LogEstToInt(pLoop->nOut));
- }else{
- sqlite3StrAccumAppend(&str, " (~1 row)", 9);
- }
-#endif
- zMsg = sqlite3StrAccumFinish(&str);
- ret = sqlite3VdbeAddOp4(v, OP_Explain, iId, iLevel, iFrom, zMsg,P4_DYNAMIC);
- }
- return ret;
-}
-#else
-# define explainOneScan(u,v,w,x,y,z) 0
-#endif /* SQLITE_OMIT_EXPLAIN */
-
-#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
-/*
-** Configure the VM passed as the first argument with an
-** sqlite3_stmt_scanstatus() entry corresponding to the scan used to
-** implement level pLvl. Argument pSrclist is a pointer to the FROM
-** clause that the scan reads data from.
-**
-** If argument addrExplain is not 0, it must be the address of an
-** OP_Explain instruction that describes the same loop.
-*/
-static void addScanStatus(
- Vdbe *v, /* Vdbe to add scanstatus entry to */
- SrcList *pSrclist, /* FROM clause pLvl reads data from */
- WhereLevel *pLvl, /* Level to add scanstatus() entry for */
- int addrExplain /* Address of OP_Explain (or 0) */
-){
- const char *zObj = 0;
- WhereLoop *pLoop = pLvl->pWLoop;
- if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 && pLoop->u.btree.pIndex!=0 ){
- zObj = pLoop->u.btree.pIndex->zName;
- }else{
- zObj = pSrclist->a[pLvl->iFrom].zName;
- }
- sqlite3VdbeScanStatus(
- v, addrExplain, pLvl->addrBody, pLvl->addrVisit, pLoop->nOut, zObj
- );
-}
-#else
-# define addScanStatus(a, b, c, d) ((void)d)
-#endif
-
-/*
-** If the most recently coded instruction is a constant range contraint
-** that originated from the LIKE optimization, then change the P3 to be
-** pLoop->iLikeRepCntr and set P5.
-**
-** The LIKE optimization trys to evaluate "x LIKE 'abc%'" as a range
-** expression: "x>='ABC' AND x<'abd'". But this requires that the range
-** scan loop run twice, once for strings and a second time for BLOBs.
-** The OP_String opcodes on the second pass convert the upper and lower
-** bound string contants to blobs. This routine makes the necessary changes
-** to the OP_String opcodes for that to happen.
-*/
-static void whereLikeOptimizationStringFixup(
- Vdbe *v, /* prepared statement under construction */
- WhereLevel *pLevel, /* The loop that contains the LIKE operator */
- WhereTerm *pTerm /* The upper or lower bound just coded */
-){
- if( pTerm->wtFlags & TERM_LIKEOPT ){
- VdbeOp *pOp;
- assert( pLevel->iLikeRepCntr>0 );
- pOp = sqlite3VdbeGetOp(v, -1);
- assert( pOp!=0 );
- assert( pOp->opcode==OP_String8
- || pTerm->pWC->pWInfo->pParse->db->mallocFailed );
- pOp->p3 = pLevel->iLikeRepCntr;
- pOp->p5 = 1;
- }
-}
-
-/*
-** Generate code for the start of the iLevel-th loop in the WHERE clause
-** implementation described by pWInfo.
-*/
-static Bitmask codeOneLoopStart(
- WhereInfo *pWInfo, /* Complete information about the WHERE clause */
- int iLevel, /* Which level of pWInfo->a[] should be coded */
- Bitmask notReady /* Which tables are currently available */
-){
- int j, k; /* Loop counters */
- int iCur; /* The VDBE cursor for the table */
- int addrNxt; /* Where to jump to continue with the next IN case */
- int omitTable; /* True if we use the index only */
- int bRev; /* True if we need to scan in reverse order */
- WhereLevel *pLevel; /* The where level to be coded */
- WhereLoop *pLoop; /* The WhereLoop object being coded */
- WhereClause *pWC; /* Decomposition of the entire WHERE clause */
- WhereTerm *pTerm; /* A WHERE clause term */
- Parse *pParse; /* Parsing context */
- sqlite3 *db; /* Database connection */
- Vdbe *v; /* The prepared stmt under constructions */
- struct SrcList_item *pTabItem; /* FROM clause term being coded */
- int addrBrk; /* Jump here to break out of the loop */
- int addrCont; /* Jump here to continue with next cycle */
- int iRowidReg = 0; /* Rowid is stored in this register, if not zero */
- int iReleaseReg = 0; /* Temp register to free before returning */
-
- pParse = pWInfo->pParse;
- v = pParse->pVdbe;
- pWC = &pWInfo->sWC;
- db = pParse->db;
- pLevel = &pWInfo->a[iLevel];
- pLoop = pLevel->pWLoop;
- pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
- iCur = pTabItem->iCursor;
- pLevel->notReady = notReady & ~getMask(&pWInfo->sMaskSet, iCur);
- bRev = (pWInfo->revMask>>iLevel)&1;
- omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0
- && (pWInfo->wctrlFlags & WHERE_FORCE_TABLE)==0;
- 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.
- ** Jump to cont to go immediately to the next iteration of the
- ** loop.
- **
- ** When there is an IN operator, we also have a "addrNxt" label that
- ** means to continue with the next IN value combination. When
- ** there are no IN operators in the constraints, the "addrNxt" label
- ** is the same as "addrBrk".
- */
- addrBrk = pLevel->addrBrk = pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
- addrCont = pLevel->addrCont = sqlite3VdbeMakeLabel(v);
-
- /* If this is the right table of a LEFT OUTER JOIN, allocate and
- ** initialize a memory cell that records if this table matches any
- ** row of the left table of the join.
- */
- if( pLevel->iFrom>0 && (pTabItem[0].jointype & JT_LEFT)!=0 ){
- pLevel->iLeftJoin = ++pParse->nMem;
- sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
- VdbeComment((v, "init LEFT JOIN no-match flag"));
- }
-
- /* Special case of a FROM clause subquery implemented as a co-routine */
- if( pTabItem->viaCoroutine ){
- int regYield = pTabItem->regReturn;
- sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);
- pLevel->p2 = sqlite3VdbeAddOp2(v, OP_Yield, regYield, addrBrk);
- VdbeCoverage(v);
- VdbeComment((v, "next row of \"%s\"", pTabItem->pTab->zName));
- pLevel->op = OP_Goto;
- }else
-
-#ifndef SQLITE_OMIT_VIRTUALTABLE
- if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
- /* Case 1: The table is a virtual-table. Use the VFilter and VNext
- ** to access the data.
- */
- int iReg; /* P3 Value for OP_VFilter */
- int addrNotFound;
- int nConstraint = pLoop->nLTerm;
-
- sqlite3ExprCachePush(pParse);
- iReg = sqlite3GetTempRange(pParse, nConstraint+2);
- addrNotFound = pLevel->addrBrk;
- for(j=0; j<nConstraint; j++){
- int iTarget = iReg+j+2;
- pTerm = pLoop->aLTerm[j];
- if( pTerm==0 ) continue;
- if( pTerm->eOperator & WO_IN ){
- codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, iTarget);
- addrNotFound = pLevel->addrNxt;
- }else{
- sqlite3ExprCode(pParse, pTerm->pExpr->pRight, iTarget);
- }
- }
- sqlite3VdbeAddOp2(v, OP_Integer, pLoop->u.vtab.idxNum, iReg);
- sqlite3VdbeAddOp2(v, OP_Integer, nConstraint, iReg+1);
- sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg,
- pLoop->u.vtab.idxStr,
- pLoop->u.vtab.needFree ? P4_MPRINTF : P4_STATIC);
- VdbeCoverage(v);
- pLoop->u.vtab.needFree = 0;
- for(j=0; j<nConstraint && j<16; j++){
- if( (pLoop->u.vtab.omitMask>>j)&1 ){
- disableTerm(pLevel, pLoop->aLTerm[j]);
- }
- }
- pLevel->op = OP_VNext;
- pLevel->p1 = iCur;
- pLevel->p2 = sqlite3VdbeCurrentAddr(v);
- sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
- sqlite3ExprCachePop(pParse);
- }else
-#endif /* SQLITE_OMIT_VIRTUALTABLE */
-
- if( (pLoop->wsFlags & WHERE_IPK)!=0
- && (pLoop->wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_EQ))!=0
- ){
- /* Case 2: We can directly reference a single row using an
- ** equality comparison against the ROWID field. Or
- ** we reference multiple rows using a "rowid IN (...)"
- ** construct.
- */
- assert( pLoop->u.btree.nEq==1 );
- pTerm = pLoop->aLTerm[0];
- assert( pTerm!=0 );
- assert( pTerm->pExpr!=0 );
- assert( omitTable==0 );
- testcase( pTerm->wtFlags & TERM_VIRTUAL );
- iReleaseReg = ++pParse->nMem;
- iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, bRev, iReleaseReg);
- if( iRowidReg!=iReleaseReg ) sqlite3ReleaseTempReg(pParse, iReleaseReg);
- addrNxt = pLevel->addrNxt;
- sqlite3VdbeAddOp2(v, OP_MustBeInt, iRowidReg, addrNxt); VdbeCoverage(v);
- sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addrNxt, iRowidReg);
- VdbeCoverage(v);
- sqlite3ExprCacheAffinityChange(pParse, iRowidReg, 1);
- sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
- VdbeComment((v, "pk"));
- pLevel->op = OP_Noop;
- }else if( (pLoop->wsFlags & WHERE_IPK)!=0
- && (pLoop->wsFlags & WHERE_COLUMN_RANGE)!=0
- ){
- /* Case 3: We have an inequality comparison against the ROWID field.
- */
- int testOp = OP_Noop;
- int start;
- int memEndValue = 0;
- WhereTerm *pStart, *pEnd;
-
- assert( omitTable==0 );
- j = 0;
- pStart = pEnd = 0;
- if( pLoop->wsFlags & WHERE_BTM_LIMIT ) pStart = pLoop->aLTerm[j++];
- if( pLoop->wsFlags & WHERE_TOP_LIMIT ) pEnd = pLoop->aLTerm[j++];
- assert( pStart!=0 || pEnd!=0 );
- if( bRev ){
- pTerm = pStart;
- pStart = pEnd;
- pEnd = pTerm;
- }
- if( pStart ){
- Expr *pX; /* The expression that defines the start bound */
- int r1, rTemp; /* Registers for holding the start boundary */
-
- /* The following constant maps TK_xx codes into corresponding
- ** seek opcodes. It depends on a particular ordering of TK_xx
- */
- const u8 aMoveOp[] = {
- /* TK_GT */ OP_SeekGT,
- /* TK_LE */ OP_SeekLE,
- /* TK_LT */ OP_SeekLT,
- /* TK_GE */ OP_SeekGE
- };
- assert( TK_LE==TK_GT+1 ); /* Make sure the ordering.. */
- assert( TK_LT==TK_GT+2 ); /* ... of the TK_xx values... */
- assert( TK_GE==TK_GT+3 ); /* ... is correcct. */
-
- assert( (pStart->wtFlags & TERM_VNULL)==0 );
- testcase( pStart->wtFlags & TERM_VIRTUAL );
- pX = pStart->pExpr;
- assert( pX!=0 );
- testcase( pStart->leftCursor!=iCur ); /* transitive constraints */
- r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);
- sqlite3VdbeAddOp3(v, aMoveOp[pX->op-TK_GT], iCur, addrBrk, r1);
- VdbeComment((v, "pk"));
- VdbeCoverageIf(v, pX->op==TK_GT);
- VdbeCoverageIf(v, pX->op==TK_LE);
- VdbeCoverageIf(v, pX->op==TK_LT);
- VdbeCoverageIf(v, pX->op==TK_GE);
- sqlite3ExprCacheAffinityChange(pParse, r1, 1);
- sqlite3ReleaseTempReg(pParse, rTemp);
- disableTerm(pLevel, pStart);
- }else{
- sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, addrBrk);
- VdbeCoverageIf(v, bRev==0);
- VdbeCoverageIf(v, bRev!=0);
- }
- if( pEnd ){
- Expr *pX;
- pX = pEnd->pExpr;
- assert( pX!=0 );
- assert( (pEnd->wtFlags & TERM_VNULL)==0 );
- testcase( pEnd->leftCursor!=iCur ); /* Transitive constraints */
- testcase( pEnd->wtFlags & TERM_VIRTUAL );
- memEndValue = ++pParse->nMem;
- sqlite3ExprCode(pParse, pX->pRight, memEndValue);
- if( pX->op==TK_LT || pX->op==TK_GT ){
- testOp = bRev ? OP_Le : OP_Ge;
- }else{
- testOp = bRev ? OP_Lt : OP_Gt;
- }
- disableTerm(pLevel, pEnd);
- }
- start = sqlite3VdbeCurrentAddr(v);
- pLevel->op = bRev ? OP_Prev : OP_Next;
- pLevel->p1 = iCur;
- pLevel->p2 = start;
- assert( pLevel->p5==0 );
- if( testOp!=OP_Noop ){
- iRowidReg = ++pParse->nMem;
- sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);
- sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
- sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg);
- VdbeCoverageIf(v, testOp==OP_Le);
- VdbeCoverageIf(v, testOp==OP_Lt);
- VdbeCoverageIf(v, testOp==OP_Ge);
- VdbeCoverageIf(v, testOp==OP_Gt);
- sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
- }
- }else if( pLoop->wsFlags & WHERE_INDEXED ){
- /* Case 4: A scan using an index.
- **
- ** The WHERE clause may contain zero or more equality
- ** terms ("==" or "IN" operators) that refer to the N
- ** left-most columns of the index. It may also contain
- ** inequality constraints (>, <, >= or <=) on the indexed
- ** column that immediately follows the N equalities. Only
- ** the right-most column can be an inequality - the rest must
- ** use the "==" and "IN" operators. For example, if the
- ** index is on (x,y,z), then the following clauses are all
- ** optimized:
- **
- ** x=5
- ** x=5 AND y=10
- ** x=5 AND y<10
- ** x=5 AND y>5 AND y<10
- ** x=5 AND y=5 AND z<=10
- **
- ** The z<10 term of the following cannot be used, only
- ** the x=5 term:
- **
- ** x=5 AND z<10
- **
- ** N may be zero if there are inequality constraints.
- ** If there are no inequality constraints, then N is at
- ** least one.
- **
- ** This case is also used when there are no WHERE clause
- ** constraints but an index is selected anyway, in order
- ** to force the output order to conform to an ORDER BY.
- */
- static const u8 aStartOp[] = {
- 0,
- 0,
- OP_Rewind, /* 2: (!start_constraints && startEq && !bRev) */
- OP_Last, /* 3: (!start_constraints && startEq && bRev) */
- OP_SeekGT, /* 4: (start_constraints && !startEq && !bRev) */
- OP_SeekLT, /* 5: (start_constraints && !startEq && bRev) */
- OP_SeekGE, /* 6: (start_constraints && startEq && !bRev) */
- OP_SeekLE /* 7: (start_constraints && startEq && bRev) */
- };
- static const u8 aEndOp[] = {
- OP_IdxGE, /* 0: (end_constraints && !bRev && !endEq) */
- OP_IdxGT, /* 1: (end_constraints && !bRev && endEq) */
- OP_IdxLE, /* 2: (end_constraints && bRev && !endEq) */
- OP_IdxLT, /* 3: (end_constraints && bRev && endEq) */
- };
- u16 nEq = pLoop->u.btree.nEq; /* Number of == or IN terms */
- int regBase; /* Base register holding constraint values */
- WhereTerm *pRangeStart = 0; /* Inequality constraint at range start */
- WhereTerm *pRangeEnd = 0; /* Inequality constraint at range end */
- int startEq; /* True if range start uses ==, >= or <= */
- int endEq; /* True if range end uses ==, >= or <= */
- int start_constraints; /* Start of range is constrained */
- int nConstraint; /* Number of constraint terms */
- Index *pIdx; /* The index we will be using */
- int iIdxCur; /* The VDBE cursor for the index */
- int nExtraReg = 0; /* Number of extra registers needed */
- int op; /* Instruction opcode */
- char *zStartAff; /* Affinity for start of range constraint */
- char cEndAff = 0; /* Affinity for end of range constraint */
- u8 bSeekPastNull = 0; /* True to seek past initial nulls */
- u8 bStopAtNull = 0; /* Add condition to terminate at NULLs */
-
- pIdx = pLoop->u.btree.pIndex;
- iIdxCur = pLevel->iIdxCur;
- assert( nEq>=pLoop->nSkip );
-
- /* If this loop satisfies a sort order (pOrderBy) request that
- ** was passed to this function to implement a "SELECT min(x) ..."
- ** query, then the caller will only allow the loop to run for
- ** a single iteration. This means that the first row returned
- ** should not have a NULL value stored in 'x'. If column 'x' is
- ** the first one after the nEq equality constraints in the index,
- ** this requires some special handling.
- */
- assert( pWInfo->pOrderBy==0
- || pWInfo->pOrderBy->nExpr==1
- || (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0 );
- if( (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)!=0
- && pWInfo->nOBSat>0
- && (pIdx->nKeyCol>nEq)
- ){
- assert( pLoop->nSkip==0 );
- bSeekPastNull = 1;
- nExtraReg = 1;
- }
-
- /* Find any inequality constraint terms for the start and end
- ** of the range.
- */
- j = nEq;
- if( pLoop->wsFlags & WHERE_BTM_LIMIT ){
- pRangeStart = pLoop->aLTerm[j++];
- nExtraReg = 1;
- /* Like optimization range constraints always occur in pairs */
- assert( (pRangeStart->wtFlags & TERM_LIKEOPT)==0 ||
- (pLoop->wsFlags & WHERE_TOP_LIMIT)!=0 );
- }
- if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
- pRangeEnd = pLoop->aLTerm[j++];
- nExtraReg = 1;
- if( (pRangeEnd->wtFlags & TERM_LIKEOPT)!=0 ){
- assert( pRangeStart!=0 ); /* LIKE opt constraints */
- assert( pRangeStart->wtFlags & TERM_LIKEOPT ); /* occur in pairs */
- pLevel->iLikeRepCntr = ++pParse->nMem;
- testcase( bRev );
- testcase( pIdx->aSortOrder[nEq]==SQLITE_SO_DESC );
- sqlite3VdbeAddOp2(v, OP_Integer,
- bRev ^ (pIdx->aSortOrder[nEq]==SQLITE_SO_DESC),
- pLevel->iLikeRepCntr);
- VdbeComment((v, "LIKE loop counter"));
- pLevel->addrLikeRep = sqlite3VdbeCurrentAddr(v);
- }
- if( pRangeStart==0
- && (j = pIdx->aiColumn[nEq])>=0
- && pIdx->pTable->aCol[j].notNull==0
- ){
- bSeekPastNull = 1;
- }
- }
- assert( pRangeEnd==0 || (pRangeEnd->wtFlags & TERM_VNULL)==0 );
-
- /* Generate code to evaluate all constraint terms using == or IN
- ** and store the values of those terms in an array of registers
- ** starting at regBase.
- */
- regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);
- assert( zStartAff==0 || sqlite3Strlen30(zStartAff)>=nEq );
- if( zStartAff ) cEndAff = zStartAff[nEq];
- addrNxt = pLevel->addrNxt;
-
- /* If we are doing a reverse order scan on an ascending index, or
- ** a forward order scan on a descending index, interchange the
- ** start and end terms (pRangeStart and pRangeEnd).
- */
- if( (nEq<pIdx->nKeyCol && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC))
- || (bRev && pIdx->nKeyCol==nEq)
- ){
- SWAP(WhereTerm *, pRangeEnd, pRangeStart);
- SWAP(u8, bSeekPastNull, bStopAtNull);
- }
-
- testcase( pRangeStart && (pRangeStart->eOperator & WO_LE)!=0 );
- testcase( pRangeStart && (pRangeStart->eOperator & WO_GE)!=0 );
- testcase( pRangeEnd && (pRangeEnd->eOperator & WO_LE)!=0 );
- testcase( pRangeEnd && (pRangeEnd->eOperator & WO_GE)!=0 );
- startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
- endEq = !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
- start_constraints = pRangeStart || nEq>0;
-
- /* Seek the index cursor to the start of the range. */
- nConstraint = nEq;
- if( pRangeStart ){
- Expr *pRight = pRangeStart->pExpr->pRight;
- sqlite3ExprCode(pParse, pRight, regBase+nEq);
- whereLikeOptimizationStringFixup(v, pLevel, pRangeStart);
- if( (pRangeStart->wtFlags & TERM_VNULL)==0
- && sqlite3ExprCanBeNull(pRight)
- ){
- sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
- VdbeCoverage(v);
- }
- if( zStartAff ){
- if( sqlite3CompareAffinity(pRight, zStartAff[nEq])==SQLITE_AFF_BLOB){
- /* Since the comparison is to be performed with no conversions
- ** applied to the operands, set the affinity to apply to pRight to
- ** SQLITE_AFF_BLOB. */
- zStartAff[nEq] = SQLITE_AFF_BLOB;
- }
- if( sqlite3ExprNeedsNoAffinityChange(pRight, zStartAff[nEq]) ){
- zStartAff[nEq] = SQLITE_AFF_BLOB;
- }
- }
- nConstraint++;
- testcase( pRangeStart->wtFlags & TERM_VIRTUAL );
- }else if( bSeekPastNull ){
- sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
- nConstraint++;
- startEq = 0;
- start_constraints = 1;
- }
- codeApplyAffinity(pParse, regBase, nConstraint - bSeekPastNull, zStartAff);
- op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];
- assert( op!=0 );
- sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
- VdbeCoverage(v);
- VdbeCoverageIf(v, op==OP_Rewind); testcase( op==OP_Rewind );
- VdbeCoverageIf(v, op==OP_Last); testcase( op==OP_Last );
- VdbeCoverageIf(v, op==OP_SeekGT); testcase( op==OP_SeekGT );
- VdbeCoverageIf(v, op==OP_SeekGE); testcase( op==OP_SeekGE );
- VdbeCoverageIf(v, op==OP_SeekLE); testcase( op==OP_SeekLE );
- VdbeCoverageIf(v, op==OP_SeekLT); testcase( op==OP_SeekLT );
-
- /* Load the value for the inequality constraint at the end of the
- ** range (if any).
- */
- nConstraint = nEq;
- if( pRangeEnd ){
- Expr *pRight = pRangeEnd->pExpr->pRight;
- sqlite3ExprCacheRemove(pParse, regBase+nEq, 1);
- sqlite3ExprCode(pParse, pRight, regBase+nEq);
- whereLikeOptimizationStringFixup(v, pLevel, pRangeEnd);
- if( (pRangeEnd->wtFlags & TERM_VNULL)==0
- && sqlite3ExprCanBeNull(pRight)
- ){
- sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
- VdbeCoverage(v);
- }
- if( sqlite3CompareAffinity(pRight, cEndAff)!=SQLITE_AFF_BLOB
- && !sqlite3ExprNeedsNoAffinityChange(pRight, cEndAff)
- ){
- codeApplyAffinity(pParse, regBase+nEq, 1, &cEndAff);
- }
- nConstraint++;
- testcase( pRangeEnd->wtFlags & TERM_VIRTUAL );
- }else if( bStopAtNull ){
- sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
- endEq = 0;
- nConstraint++;
- }
- sqlite3DbFree(db, zStartAff);
-
- /* Top of the loop body */
- pLevel->p2 = sqlite3VdbeCurrentAddr(v);
-
- /* Check if the index cursor is past the end of the range. */
- if( nConstraint ){
- op = aEndOp[bRev*2 + endEq];
- sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
- testcase( op==OP_IdxGT ); VdbeCoverageIf(v, op==OP_IdxGT );
- testcase( op==OP_IdxGE ); VdbeCoverageIf(v, op==OP_IdxGE );
- testcase( op==OP_IdxLT ); VdbeCoverageIf(v, op==OP_IdxLT );
- testcase( op==OP_IdxLE ); VdbeCoverageIf(v, op==OP_IdxLE );
- }
-
- /* Seek the table cursor, if required */
- disableTerm(pLevel, pRangeStart);
- disableTerm(pLevel, pRangeEnd);
- if( omitTable ){
- /* pIdx is a covering index. No need to access the main table. */
- }else if( HasRowid(pIdx->pTable) ){
- iRowidReg = ++pParse->nMem;
- sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
- sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
- sqlite3VdbeAddOp2(v, OP_Seek, iCur, iRowidReg); /* Deferred seek */
- }else if( iCur!=iIdxCur ){
- Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
- iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);
- for(j=0; j<pPk->nKeyCol; j++){
- k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
- sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);
- }
- sqlite3VdbeAddOp4Int(v, OP_NotFound, iCur, addrCont,
- iRowidReg, pPk->nKeyCol); VdbeCoverage(v);
- }
-
- /* Record the instruction used to terminate the loop. Disable
- ** WHERE clause terms made redundant by the index range scan.
- */
- if( pLoop->wsFlags & WHERE_ONEROW ){
- pLevel->op = OP_Noop;
- }else if( bRev ){
- pLevel->op = OP_Prev;
- }else{
- pLevel->op = OP_Next;
- }
- pLevel->p1 = iIdxCur;
- pLevel->p3 = (pLoop->wsFlags&WHERE_UNQ_WANTED)!=0 ? 1:0;
- if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){
- pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
- }else{
- assert( pLevel->p5==0 );
- }
- }else
-
-#ifndef SQLITE_OMIT_OR_OPTIMIZATION
- if( pLoop->wsFlags & WHERE_MULTI_OR ){
- /* Case 5: Two or more separately indexed terms connected by OR
- **
- ** Example:
- **
- ** CREATE TABLE t1(a,b,c,d);
- ** CREATE INDEX i1 ON t1(a);
- ** CREATE INDEX i2 ON t1(b);
- ** CREATE INDEX i3 ON t1(c);
- **
- ** SELECT * FROM t1 WHERE a=5 OR b=7 OR (c=11 AND d=13)
- **
- ** In the example, there are three indexed terms connected by OR.
- ** The top of the loop looks like this:
- **
- ** Null 1 # Zero the rowset in reg 1
- **
- ** Then, for each indexed term, the following. The arguments to
- ** RowSetTest are such that the rowid of the current row is inserted
- ** into the RowSet. If it is already present, control skips the
- ** Gosub opcode and jumps straight to the code generated by WhereEnd().
- **
- ** sqlite3WhereBegin(<term>)
- ** RowSetTest # Insert rowid into rowset
- ** Gosub 2 A
- ** sqlite3WhereEnd()
- **
- ** Following the above, code to terminate the loop. Label A, the target
- ** of the Gosub above, jumps to the instruction right after the Goto.
- **
- ** Null 1 # Zero the rowset in reg 1
- ** Goto B # The loop is finished.
- **
- ** A: <loop body> # Return data, whatever.
- **
- ** Return 2 # Jump back to the Gosub
- **
- ** B: <after the loop>
- **
- ** Added 2014-05-26: If the table is a WITHOUT ROWID table, then
- ** use an ephemeral index instead of a RowSet to record the primary
- ** keys of the rows we have already seen.
- **
- */
- WhereClause *pOrWc; /* The OR-clause broken out into subterms */
- SrcList *pOrTab; /* Shortened table list or OR-clause generation */
- Index *pCov = 0; /* Potential covering index (or NULL) */
- int iCovCur = pParse->nTab++; /* Cursor used for index scans (if any) */
-
- int regReturn = ++pParse->nMem; /* Register used with OP_Gosub */
- int regRowset = 0; /* Register for RowSet object */
- int regRowid = 0; /* Register holding rowid */
- int iLoopBody = sqlite3VdbeMakeLabel(v); /* Start of loop body */
- int iRetInit; /* Address of regReturn init */
- int untestedTerms = 0; /* Some terms not completely tested */
- int ii; /* Loop counter */
- u16 wctrlFlags; /* Flags for sub-WHERE clause */
- Expr *pAndExpr = 0; /* An ".. AND (...)" expression */
- Table *pTab = pTabItem->pTab;
-
- pTerm = pLoop->aLTerm[0];
- assert( pTerm!=0 );
- assert( pTerm->eOperator & WO_OR );
- assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
- pOrWc = &pTerm->u.pOrInfo->wc;
- pLevel->op = OP_Return;
- pLevel->p1 = regReturn;
-
- /* Set up a new SrcList in pOrTab containing the table being scanned
- ** by this loop in the a[0] slot and all notReady tables in a[1..] slots.
- ** This becomes the SrcList in the recursive call to sqlite3WhereBegin().
- */
- if( pWInfo->nLevel>1 ){
- int nNotReady; /* The number of notReady tables */
- struct SrcList_item *origSrc; /* Original list of tables */
- nNotReady = pWInfo->nLevel - iLevel - 1;
- pOrTab = sqlite3StackAllocRaw(db,
- sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0]));
- if( pOrTab==0 ) return notReady;
- pOrTab->nAlloc = (u8)(nNotReady + 1);
- pOrTab->nSrc = pOrTab->nAlloc;
- memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem));
- origSrc = pWInfo->pTabList->a;
- for(k=1; k<=nNotReady; k++){
- memcpy(&pOrTab->a[k], &origSrc[pLevel[k].iFrom], sizeof(pOrTab->a[k]));
- }
- }else{
- pOrTab = pWInfo->pTabList;
- }
-
- /* Initialize the rowset register to contain NULL. An SQL NULL is
- ** equivalent to an empty rowset. Or, create an ephemeral index
- ** capable of holding primary keys in the case of a WITHOUT ROWID.
- **
- ** Also initialize regReturn to contain the address of the instruction
- ** immediately following the OP_Return at the bottom of the loop. This
- ** is required in a few obscure LEFT JOIN cases where control jumps
- ** over the top of the loop into the body of it. In this case the
- ** correct response for the end-of-loop code (the OP_Return) is to
- ** fall through to the next instruction, just as an OP_Next does if
- ** called on an uninitialized cursor.
- */
- if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
- if( HasRowid(pTab) ){
- regRowset = ++pParse->nMem;
- sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);
- }else{
- Index *pPk = sqlite3PrimaryKeyIndex(pTab);
- regRowset = pParse->nTab++;
- sqlite3VdbeAddOp2(v, OP_OpenEphemeral, regRowset, pPk->nKeyCol);
- sqlite3VdbeSetP4KeyInfo(pParse, pPk);
- }
- regRowid = ++pParse->nMem;
- }
- iRetInit = sqlite3VdbeAddOp2(v, OP_Integer, 0, regReturn);
-
- /* If the original WHERE clause is z of the form: (x1 OR x2 OR ...) AND y
- ** Then for every term xN, evaluate as the subexpression: xN AND z
- ** That way, terms in y that are factored into the disjunction will
- ** be picked up by the recursive calls to sqlite3WhereBegin() below.
- **
- ** Actually, each subexpression is converted to "xN AND w" where w is
- ** the "interesting" terms of z - terms that did not originate in the
- ** ON or USING clause of a LEFT JOIN, and terms that are usable as
- ** indices.
- **
- ** This optimization also only applies if the (x1 OR x2 OR ...) term
- ** is not contained in the ON clause of a LEFT JOIN.
- ** See ticket http://www.sqlite.org/src/info/f2369304e4
- */
- if( pWC->nTerm>1 ){
- int iTerm;
- for(iTerm=0; iTerm<pWC->nTerm; iTerm++){
- Expr *pExpr = pWC->a[iTerm].pExpr;
- if( &pWC->a[iTerm] == pTerm ) continue;
- if( ExprHasProperty(pExpr, EP_FromJoin) ) continue;
- if( (pWC->a[iTerm].wtFlags & TERM_VIRTUAL)!=0 ) continue;
- if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
- testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
- pExpr = sqlite3ExprDup(db, pExpr, 0);
- pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr);
- }
- if( pAndExpr ){
- pAndExpr = sqlite3PExpr(pParse, TK_AND, 0, pAndExpr, 0);
- }
- }
-
- /* Run a separate WHERE clause for each term of the OR clause. After
- ** eliminating duplicates from other WHERE clauses, the action for each
- ** sub-WHERE clause is to to invoke the main loop body as a subroutine.
- */
- wctrlFlags = WHERE_OMIT_OPEN_CLOSE
- | WHERE_FORCE_TABLE
- | WHERE_ONETABLE_ONLY
- | WHERE_NO_AUTOINDEX;
- for(ii=0; ii<pOrWc->nTerm; ii++){
- WhereTerm *pOrTerm = &pOrWc->a[ii];
- if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){
- WhereInfo *pSubWInfo; /* Info for single OR-term scan */
- Expr *pOrExpr = pOrTerm->pExpr; /* Current OR clause term */
- int j1 = 0; /* Address of jump operation */
- if( pAndExpr && !ExprHasProperty(pOrExpr, EP_FromJoin) ){
- pAndExpr->pLeft = pOrExpr;
- pOrExpr = pAndExpr;
- }
- /* Loop through table entries that match term pOrTerm. */
- WHERETRACE(0xffff, ("Subplan for OR-clause:\n"));
- pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0,
- wctrlFlags, iCovCur);
- assert( pSubWInfo || pParse->nErr || db->mallocFailed );
- if( pSubWInfo ){
- WhereLoop *pSubLoop;
- int addrExplain = explainOneScan(
- pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0
- );
- addScanStatus(v, pOrTab, &pSubWInfo->a[0], addrExplain);
-
- /* This is the sub-WHERE clause body. First skip over
- ** duplicate rows from prior sub-WHERE clauses, and record the
- ** rowid (or PRIMARY KEY) for the current row so that the same
- ** row will be skipped in subsequent sub-WHERE clauses.
- */
- if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
- int r;
- int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
- if( HasRowid(pTab) ){
- r = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, regRowid, 0);
- j1 = sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, 0, r,iSet);
- VdbeCoverage(v);
- }else{
- Index *pPk = sqlite3PrimaryKeyIndex(pTab);
- int nPk = pPk->nKeyCol;
- int iPk;
-
- /* Read the PK into an array of temp registers. */
- r = sqlite3GetTempRange(pParse, nPk);
- for(iPk=0; iPk<nPk; iPk++){
- int iCol = pPk->aiColumn[iPk];
- sqlite3ExprCodeGetColumn(pParse, pTab, iCol, iCur, r+iPk, 0);
- }
-
- /* Check if the temp table already contains this key. If so,
- ** the row has already been included in the result set and
- ** can be ignored (by jumping past the Gosub below). Otherwise,
- ** insert the key into the temp table and proceed with processing
- ** the row.
- **
- ** Use some of the same optimizations as OP_RowSetTest: If iSet
- ** is zero, assume that the key cannot already be present in
- ** the temp table. And if iSet is -1, assume that there is no
- ** need to insert the key into the temp table, as it will never
- ** be tested for. */
- if( iSet ){
- j1 = sqlite3VdbeAddOp4Int(v, OP_Found, regRowset, 0, r, nPk);
- VdbeCoverage(v);
- }
- if( iSet>=0 ){
- sqlite3VdbeAddOp3(v, OP_MakeRecord, r, nPk, regRowid);
- sqlite3VdbeAddOp3(v, OP_IdxInsert, regRowset, regRowid, 0);
- if( iSet ) sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
- }
-
- /* Release the array of temp registers */
- sqlite3ReleaseTempRange(pParse, r, nPk);
- }
- }
-
- /* Invoke the main loop body as a subroutine */
- sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody);
-
- /* Jump here (skipping the main loop body subroutine) if the
- ** current sub-WHERE row is a duplicate from prior sub-WHEREs. */
- if( j1 ) sqlite3VdbeJumpHere(v, j1);
-
- /* The pSubWInfo->untestedTerms flag means that this OR term
- ** contained one or more AND term from a notReady table. The
- ** terms from the notReady table could not be tested and will
- ** need to be tested later.
- */
- if( pSubWInfo->untestedTerms ) untestedTerms = 1;
-
- /* If all of the OR-connected terms are optimized using the same
- ** index, and the index is opened using the same cursor number
- ** by each call to sqlite3WhereBegin() made by this loop, it may
- ** be possible to use that index as a covering index.
- **
- ** If the call to sqlite3WhereBegin() above resulted in a scan that
- ** uses an index, and this is either the first OR-connected term
- ** processed or the index is the same as that used by all previous
- ** terms, set pCov to the candidate covering index. Otherwise, set
- ** pCov to NULL to indicate that no candidate covering index will
- ** be available.
- */
- pSubLoop = pSubWInfo->a[0].pWLoop;
- assert( (pSubLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
- if( (pSubLoop->wsFlags & WHERE_INDEXED)!=0
- && (ii==0 || pSubLoop->u.btree.pIndex==pCov)
- && (HasRowid(pTab) || !IsPrimaryKeyIndex(pSubLoop->u.btree.pIndex))
- ){
- assert( pSubWInfo->a[0].iIdxCur==iCovCur );
- pCov = pSubLoop->u.btree.pIndex;
- wctrlFlags |= WHERE_REOPEN_IDX;
- }else{
- pCov = 0;
- }
-
- /* Finish the loop through table entries that match term pOrTerm. */
- sqlite3WhereEnd(pSubWInfo);
- }
- }
- }
- pLevel->u.pCovidx = pCov;
- if( pCov ) pLevel->iIdxCur = iCovCur;
- if( pAndExpr ){
- pAndExpr->pLeft = 0;
- sqlite3ExprDelete(db, pAndExpr);
- }
- sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));
- sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrBrk);
- sqlite3VdbeResolveLabel(v, iLoopBody);
-
- if( pWInfo->nLevel>1 ) sqlite3StackFree(db, pOrTab);
- if( !untestedTerms ) disableTerm(pLevel, pTerm);
- }else
-#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
-
- {
- /* Case 6: There is no usable index. We must do a complete
- ** scan of the entire table.
- */
- static const u8 aStep[] = { OP_Next, OP_Prev };
- static const u8 aStart[] = { OP_Rewind, OP_Last };
- assert( bRev==0 || bRev==1 );
- if( pTabItem->isRecursive ){
- /* Tables marked isRecursive have only a single row that is stored in
- ** a pseudo-cursor. No need to Rewind or Next such cursors. */
- pLevel->op = OP_Noop;
- }else{
- pLevel->op = aStep[bRev];
- pLevel->p1 = iCur;
- pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);
- VdbeCoverageIf(v, bRev==0);
- VdbeCoverageIf(v, bRev!=0);
- pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
- }
- }
-
-#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
- pLevel->addrVisit = sqlite3VdbeCurrentAddr(v);
-#endif
-
- /* Insert code to test every subexpression that can be completely
- ** computed using the current set of tables.
- */
- for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
- Expr *pE;
- int skipLikeAddr = 0;
- testcase( pTerm->wtFlags & TERM_VIRTUAL );
- testcase( pTerm->wtFlags & TERM_CODED );
- if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
- if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
- testcase( pWInfo->untestedTerms==0
- && (pWInfo->wctrlFlags & WHERE_ONETABLE_ONLY)!=0 );
- pWInfo->untestedTerms = 1;
- continue;
- }
- pE = pTerm->pExpr;
- assert( pE!=0 );
- if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
- continue;
- }
- if( pTerm->wtFlags & TERM_LIKECOND ){
- assert( pLevel->iLikeRepCntr>0 );
- skipLikeAddr = sqlite3VdbeAddOp1(v, OP_IfNot, pLevel->iLikeRepCntr);
- VdbeCoverage(v);
- }
- sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
- if( skipLikeAddr ) sqlite3VdbeJumpHere(v, skipLikeAddr);
- pTerm->wtFlags |= TERM_CODED;
- }
-
- /* Insert code to test for implied constraints based on transitivity
- ** of the "==" operator.
- **
- ** Example: If the WHERE clause contains "t1.a=t2.b" and "t2.b=123"
- ** and we are coding the t1 loop and the t2 loop has not yet coded,
- ** then we cannot use the "t1.a=t2.b" constraint, but we can code
- ** the implied "t1.a=123" constraint.
- */
- for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
- Expr *pE, *pEAlt;
- WhereTerm *pAlt;
- if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
- if( (pTerm->eOperator & (WO_EQ|WO_IS))==0 ) continue;
- if( (pTerm->eOperator & WO_EQUIV)==0 ) continue;
- if( pTerm->leftCursor!=iCur ) continue;
- if( pLevel->iLeftJoin ) continue;
- pE = pTerm->pExpr;
- assert( !ExprHasProperty(pE, EP_FromJoin) );
- assert( (pTerm->prereqRight & pLevel->notReady)!=0 );
- pAlt = findTerm(pWC, iCur, pTerm->u.leftColumn, notReady,
- WO_EQ|WO_IN|WO_IS, 0);
- if( pAlt==0 ) continue;
- if( pAlt->wtFlags & (TERM_CODED) ) continue;
- testcase( pAlt->eOperator & WO_EQ );
- testcase( pAlt->eOperator & WO_IS );
- testcase( pAlt->eOperator & WO_IN );
- VdbeModuleComment((v, "begin transitive constraint"));
- pEAlt = sqlite3StackAllocRaw(db, sizeof(*pEAlt));
- if( pEAlt ){
- *pEAlt = *pAlt->pExpr;
- pEAlt->pLeft = pE->pLeft;
- sqlite3ExprIfFalse(pParse, pEAlt, addrCont, SQLITE_JUMPIFNULL);
- sqlite3StackFree(db, pEAlt);
- }
- }
-
- /* For a LEFT OUTER JOIN, generate code that will record the fact that
- ** at least one row of the right table has matched the left table.
- */
- if( pLevel->iLeftJoin ){
- pLevel->addrFirst = sqlite3VdbeCurrentAddr(v);
- sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
- VdbeComment((v, "record LEFT JOIN hit"));
- sqlite3ExprCacheClear(pParse);
- for(pTerm=pWC->a, j=0; j<pWC->nTerm; j++, pTerm++){
- testcase( pTerm->wtFlags & TERM_VIRTUAL );
- testcase( pTerm->wtFlags & TERM_CODED );
- if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
- if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
- assert( pWInfo->untestedTerms );
- continue;
- }
- assert( pTerm->pExpr );
- sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
- pTerm->wtFlags |= TERM_CODED;
- }
- }
-
- return pLevel->notReady;
-}
#ifdef WHERETRACE_ENABLED
/*
whereLoopInit(pNew);
for(iTab=0, pItem=pTabList->a; iTab<nTabList; iTab++, pItem++){
pNew->iTab = iTab;
- pNew->maskSelf = getMask(&pWInfo->sMaskSet, pItem->iCursor);
+ pNew->maskSelf = sqlite3WhereGetMask(&pWInfo->sMaskSet, pItem->iCursor);
if( ((pItem->jointype|priorJoinType) & (JT_LEFT|JT_CROSS))!=0 ){
mExtra = mPrior;
}
pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);
if( pOBExpr->op!=TK_COLUMN ) continue;
if( pOBExpr->iTable!=iCur ) continue;
- pTerm = findTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
+ pTerm = sqlite3WhereFindTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
~ready, WO_EQ|WO_ISNULL|WO_IS, 0);
if( pTerm==0 ) continue;
if( (pTerm->eOperator&(WO_EQ|WO_IS))!=0 && pOBExpr->iColumn>=0 ){
pLoop = pBuilder->pNew;
pLoop->wsFlags = 0;
pLoop->nSkip = 0;
- pTerm = findTerm(pWC, iCur, -1, 0, WO_EQ|WO_IS, 0);
+ pTerm = sqlite3WhereFindTerm(pWC, iCur, -1, 0, WO_EQ|WO_IS, 0);
if( pTerm ){
testcase( pTerm->eOperator & WO_IS );
pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_IPK|WHERE_ONEROW;
) continue;
opMask = pIdx->uniqNotNull ? (WO_EQ|WO_IS) : WO_EQ;
for(j=0; j<pIdx->nKeyCol; j++){
- pTerm = findTerm(pWC, iCur, pIdx->aiColumn[j], 0, opMask, pIdx);
+ pTerm = sqlite3WhereFindTerm(pWC, iCur, pIdx->aiColumn[j], 0, opMask, pIdx);
if( pTerm==0 ) break;
testcase( pTerm->eOperator & WO_IS );
pLoop->aLTerm[j] = pTerm;
if( pLoop->wsFlags ){
pLoop->nOut = (LogEst)1;
pWInfo->a[0].pWLoop = pLoop;
- pLoop->maskSelf = getMask(&pWInfo->sMaskSet, iCur);
+ pLoop->maskSelf = sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur);
pWInfo->a[0].iTabCur = iCur;
pWInfo->nRowOut = 1;
if( pWInfo->pOrderBy ) pWInfo->nOBSat = pWInfo->pOrderBy->nExpr;
{
Bitmask toTheLeft = 0;
for(ii=0; ii<pTabList->nSrc; ii++){
- Bitmask m = getMask(pMaskSet, pTabList->a[ii].iCursor);
+ Bitmask m = sqlite3WhereGetMask(pMaskSet, pTabList->a[ii].iCursor);
assert( (m-1)==toTheLeft );
toTheLeft |= m;
}
if( db->mallocFailed ) goto whereBeginError;
}
#endif
- addrExplain = explainOneScan(
+ addrExplain = sqlite3WhereExplainOneScan(
pParse, pTabList, pLevel, ii, pLevel->iFrom, wctrlFlags
);
pLevel->addrBody = sqlite3VdbeCurrentAddr(v);
- notReady = codeOneLoopStart(pWInfo, ii, notReady);
+ notReady = sqlite3WhereCodeOneLoopStart(pWInfo, ii, notReady);
pWInfo->iContinue = pLevel->addrCont;
if( (wsFlags&WHERE_MULTI_OR)==0 && (wctrlFlags&WHERE_ONETABLE_ONLY)==0 ){
- addScanStatus(v, pTabList, pLevel, addrExplain);
+ sqlite3WhereAddScanStatus(v, pTabList, pLevel, addrExplain);
}
}
** Trace output macros
*/
#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
-/***/ int sqlite3WhereTrace = 0;
+/***/ int sqlite3WhereTrace;
#endif
#if defined(SQLITE_DEBUG) \
&& (defined(SQLITE_TEST) || defined(SQLITE_ENABLE_WHERETRACE))
WhereOrCost a[N_OR_COST]; /* Set of best costs */
};
-
-/* Forward declaration of methods */
-static int whereLoopResize(sqlite3*, WhereLoop*, int);
-
/*
** Each instance of this object holds a sequence of WhereLoop objects
** that implement some or all of a query plan.
WhereLevel a[1]; /* Information about each nest loop in WHERE */
};
+/*
+** Private interfaces - callable only by other where.c routines.
+*/
+Bitmask sqlite3WhereGetMask(WhereMaskSet*,int);
+WhereTerm *sqlite3WhereFindTerm(
+ WhereClause *pWC, /* The WHERE clause to be searched */
+ int iCur, /* Cursor number of LHS */
+ int iColumn, /* Column number of LHS */
+ Bitmask notReady, /* RHS must not overlap with this mask */
+ u32 op, /* Mask of WO_xx values describing operator */
+ Index *pIdx /* Must be compatible with this index, if not NULL */
+);
+#ifndef SQLITE_OMIT_EXPLAIN
+int sqlite3WhereExplainOneScan(
+ Parse *pParse, /* Parse context */
+ SrcList *pTabList, /* Table list this loop refers to */
+ WhereLevel *pLevel, /* Scan to write OP_Explain opcode for */
+ int iLevel, /* Value for "level" column of output */
+ int iFrom, /* Value for "from" column of output */
+ u16 wctrlFlags /* Flags passed to sqlite3WhereBegin() */
+);
+#else
+# define sqlite3WhereExplainOneScan(u,v,w,x,y,z) 0
+#endif /* SQLITE_OMIT_EXPLAIN */
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+void sqlite3WhereAddScanStatus(
+ Vdbe *v, /* Vdbe to add scanstatus entry to */
+ SrcList *pSrclist, /* FROM clause pLvl reads data from */
+ WhereLevel *pLvl, /* Level to add scanstatus() entry for */
+ int addrExplain /* Address of OP_Explain (or 0) */
+);
+#else
+# define sqlite3WhereAddScanStatus(a, b, c, d) ((void)d)
+#endif
+Bitmask sqlite3WhereCodeOneLoopStart(
+ WhereInfo *pWInfo, /* Complete information about the WHERE clause */
+ int iLevel, /* Which level of pWInfo->a[] should be coded */
+ Bitmask notReady /* Which tables are currently available */
+);
+
+
+
+
+
+
+
/*
** Bitmasks for the operators on WhereTerm objects. These are all
** operators that are of interest to the query planner. An
--- /dev/null
+/*
+** 2015-06-06
+**
+** 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 module contains C code that generates VDBE code used to process
+** the WHERE clause of SQL statements.
+**
+** This file was split off from where.c on 2015-06-06 in order to reduce the
+** size of where.c and make it easier to edit. This file contains the routines
+** that actually generate the bulk of the WHERE loop code. The original where.c
+** file retains the code that does query planning and analysis.
+*/
+#include "sqliteInt.h"
+#include "whereInt.h"
+
+#ifndef SQLITE_OMIT_EXPLAIN
+/*
+** This routine is a helper for explainIndexRange() below
+**
+** pStr holds the text of an expression that we are building up one term
+** at a time. This routine adds a new term to the end of the expression.
+** Terms are separated by AND so add the "AND" text for second and subsequent
+** terms only.
+*/
+static void explainAppendTerm(
+ StrAccum *pStr, /* The text expression being built */
+ int iTerm, /* Index of this term. First is zero */
+ const char *zColumn, /* Name of the column */
+ const char *zOp /* Name of the operator */
+){
+ if( iTerm ) sqlite3StrAccumAppend(pStr, " AND ", 5);
+ sqlite3StrAccumAppendAll(pStr, zColumn);
+ sqlite3StrAccumAppend(pStr, zOp, 1);
+ sqlite3StrAccumAppend(pStr, "?", 1);
+}
+
+/*
+** Argument pLevel describes a strategy for scanning table pTab. This
+** function appends text to pStr that describes the subset of table
+** rows scanned by the strategy in the form of an SQL expression.
+**
+** For example, if the query:
+**
+** SELECT * FROM t1 WHERE a=1 AND b>2;
+**
+** is run and there is an index on (a, b), then this function returns a
+** string similar to:
+**
+** "a=? AND b>?"
+*/
+static void explainIndexRange(StrAccum *pStr, WhereLoop *pLoop, Table *pTab){
+ Index *pIndex = pLoop->u.btree.pIndex;
+ u16 nEq = pLoop->u.btree.nEq;
+ u16 nSkip = pLoop->nSkip;
+ int i, j;
+ Column *aCol = pTab->aCol;
+ i16 *aiColumn = pIndex->aiColumn;
+
+ if( nEq==0 && (pLoop->wsFlags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ) return;
+ sqlite3StrAccumAppend(pStr, " (", 2);
+ for(i=0; i<nEq; i++){
+ char *z = aiColumn[i] < 0 ? "rowid" : aCol[aiColumn[i]].zName;
+ if( i>=nSkip ){
+ explainAppendTerm(pStr, i, z, "=");
+ }else{
+ if( i ) sqlite3StrAccumAppend(pStr, " AND ", 5);
+ sqlite3XPrintf(pStr, 0, "ANY(%s)", z);
+ }
+ }
+
+ j = i;
+ if( pLoop->wsFlags&WHERE_BTM_LIMIT ){
+ char *z = aiColumn[j] < 0 ? "rowid" : aCol[aiColumn[j]].zName;
+ explainAppendTerm(pStr, i++, z, ">");
+ }
+ if( pLoop->wsFlags&WHERE_TOP_LIMIT ){
+ char *z = aiColumn[j] < 0 ? "rowid" : aCol[aiColumn[j]].zName;
+ explainAppendTerm(pStr, i, z, "<");
+ }
+ sqlite3StrAccumAppend(pStr, ")", 1);
+}
+
+/*
+** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN
+** command, or if either SQLITE_DEBUG or SQLITE_ENABLE_STMT_SCANSTATUS was
+** defined at compile-time. If it is not a no-op, a single OP_Explain opcode
+** is added to the output to describe the table scan strategy in pLevel.
+**
+** 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 sqlite3WhereExplainOneScan(
+ Parse *pParse, /* Parse context */
+ SrcList *pTabList, /* Table list this loop refers to */
+ WhereLevel *pLevel, /* Scan to write OP_Explain opcode for */
+ int iLevel, /* Value for "level" column of output */
+ int iFrom, /* Value for "from" column of output */
+ u16 wctrlFlags /* Flags passed to sqlite3WhereBegin() */
+){
+ int ret = 0;
+#if !defined(SQLITE_DEBUG) && !defined(SQLITE_ENABLE_STMT_SCANSTATUS)
+ if( pParse->explain==2 )
+#endif
+ {
+ struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
+ Vdbe *v = pParse->pVdbe; /* VM being constructed */
+ sqlite3 *db = pParse->db; /* Database handle */
+ int iId = pParse->iSelectId; /* Select id (left-most output column) */
+ int isSearch; /* True for a SEARCH. False for SCAN. */
+ WhereLoop *pLoop; /* The controlling WhereLoop object */
+ u32 flags; /* Flags that describe this loop */
+ char *zMsg; /* Text to add to EQP output */
+ StrAccum str; /* EQP output string */
+ char zBuf[100]; /* Initial space for EQP output string */
+
+ pLoop = pLevel->pWLoop;
+ flags = pLoop->wsFlags;
+ if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_ONETABLE_ONLY) ) return 0;
+
+ isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
+ || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
+ || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));
+
+ sqlite3StrAccumInit(&str, db, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
+ sqlite3StrAccumAppendAll(&str, isSearch ? "SEARCH" : "SCAN");
+ if( pItem->pSelect ){
+ sqlite3XPrintf(&str, 0, " SUBQUERY %d", pItem->iSelectId);
+ }else{
+ sqlite3XPrintf(&str, 0, " TABLE %s", pItem->zName);
+ }
+
+ if( pItem->zAlias ){
+ sqlite3XPrintf(&str, 0, " AS %s", pItem->zAlias);
+ }
+ if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 ){
+ const char *zFmt = 0;
+ Index *pIdx;
+
+ assert( pLoop->u.btree.pIndex!=0 );
+ pIdx = pLoop->u.btree.pIndex;
+ assert( !(flags&WHERE_AUTO_INDEX) || (flags&WHERE_IDX_ONLY) );
+ if( !HasRowid(pItem->pTab) && IsPrimaryKeyIndex(pIdx) ){
+ if( isSearch ){
+ zFmt = "PRIMARY KEY";
+ }
+ }else if( flags & WHERE_PARTIALIDX ){
+ zFmt = "AUTOMATIC PARTIAL COVERING INDEX";
+ }else if( flags & WHERE_AUTO_INDEX ){
+ zFmt = "AUTOMATIC COVERING INDEX";
+ }else if( flags & WHERE_IDX_ONLY ){
+ zFmt = "COVERING INDEX %s";
+ }else{
+ zFmt = "INDEX %s";
+ }
+ if( zFmt ){
+ sqlite3StrAccumAppend(&str, " USING ", 7);
+ sqlite3XPrintf(&str, 0, zFmt, pIdx->zName);
+ explainIndexRange(&str, pLoop, pItem->pTab);
+ }
+ }else if( (flags & WHERE_IPK)!=0 && (flags & WHERE_CONSTRAINT)!=0 ){
+ const char *zRange;
+ if( flags&(WHERE_COLUMN_EQ|WHERE_COLUMN_IN) ){
+ zRange = "(rowid=?)";
+ }else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){
+ zRange = "(rowid>? AND rowid<?)";
+ }else if( flags&WHERE_BTM_LIMIT ){
+ zRange = "(rowid>?)";
+ }else{
+ assert( flags&WHERE_TOP_LIMIT);
+ zRange = "(rowid<?)";
+ }
+ sqlite3StrAccumAppendAll(&str, " USING INTEGER PRIMARY KEY ");
+ sqlite3StrAccumAppendAll(&str, zRange);
+ }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+ else if( (flags & WHERE_VIRTUALTABLE)!=0 ){
+ sqlite3XPrintf(&str, 0, " VIRTUAL TABLE INDEX %d:%s",
+ pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr);
+ }
+#endif
+#ifdef SQLITE_EXPLAIN_ESTIMATED_ROWS
+ if( pLoop->nOut>=10 ){
+ sqlite3XPrintf(&str, 0, " (~%llu rows)", sqlite3LogEstToInt(pLoop->nOut));
+ }else{
+ sqlite3StrAccumAppend(&str, " (~1 row)", 9);
+ }
+#endif
+ zMsg = sqlite3StrAccumFinish(&str);
+ ret = sqlite3VdbeAddOp4(v, OP_Explain, iId, iLevel, iFrom, zMsg,P4_DYNAMIC);
+ }
+ return ret;
+}
+#endif /* SQLITE_OMIT_EXPLAIN */
+
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+/*
+** Configure the VM passed as the first argument with an
+** sqlite3_stmt_scanstatus() entry corresponding to the scan used to
+** implement level pLvl. Argument pSrclist is a pointer to the FROM
+** clause that the scan reads data from.
+**
+** If argument addrExplain is not 0, it must be the address of an
+** OP_Explain instruction that describes the same loop.
+*/
+void sqlite3WhereAddScanStatus(
+ Vdbe *v, /* Vdbe to add scanstatus entry to */
+ SrcList *pSrclist, /* FROM clause pLvl reads data from */
+ WhereLevel *pLvl, /* Level to add scanstatus() entry for */
+ int addrExplain /* Address of OP_Explain (or 0) */
+){
+ const char *zObj = 0;
+ WhereLoop *pLoop = pLvl->pWLoop;
+ if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 && pLoop->u.btree.pIndex!=0 ){
+ zObj = pLoop->u.btree.pIndex->zName;
+ }else{
+ zObj = pSrclist->a[pLvl->iFrom].zName;
+ }
+ sqlite3VdbeScanStatus(
+ v, addrExplain, pLvl->addrBody, pLvl->addrVisit, pLoop->nOut, zObj
+ );
+}
+#endif
+
+
+/*
+** Disable a term in the WHERE clause. Except, do not disable the term
+** if it controls a LEFT OUTER JOIN and it did not originate in the ON
+** or USING clause of that join.
+**
+** Consider the term t2.z='ok' in the following queries:
+**
+** (1) SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x WHERE t2.z='ok'
+** (2) SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x AND t2.z='ok'
+** (3) SELECT * FROM t1, t2 WHERE t1.a=t2.x AND t2.z='ok'
+**
+** The t2.z='ok' is disabled in the in (2) because it originates
+** in the ON clause. The term is disabled in (3) because it is not part
+** of a LEFT OUTER JOIN. In (1), the term is not disabled.
+**
+** Disabling a term causes that term to not be tested in the inner loop
+** of the join. Disabling is an optimization. When terms are satisfied
+** by indices, we disable them to prevent redundant tests in the inner
+** loop. We would get the correct results if nothing were ever disabled,
+** but joins might run a little slower. The trick is to disable as much
+** as we can without disabling too much. If we disabled in (1), we'd get
+** the wrong answer. See ticket #813.
+**
+** If all the children of a term are disabled, then that term is also
+** automatically disabled. In this way, terms get disabled if derived
+** virtual terms are tested first. For example:
+**
+** x GLOB 'abc*' AND x>='abc' AND x<'acd'
+** \___________/ \______/ \_____/
+** parent child1 child2
+**
+** Only the parent term was in the original WHERE clause. The child1
+** and child2 terms were added by the LIKE optimization. If both of
+** the virtual child terms are valid, then testing of the parent can be
+** skipped.
+**
+** Usually the parent term is marked as TERM_CODED. But if the parent
+** term was originally TERM_LIKE, then the parent gets TERM_LIKECOND instead.
+** The TERM_LIKECOND marking indicates that the term should be coded inside
+** a conditional such that is only evaluated on the second pass of a
+** LIKE-optimization loop, when scanning BLOBs instead of strings.
+*/
+static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
+ int nLoop = 0;
+ while( pTerm
+ && (pTerm->wtFlags & TERM_CODED)==0
+ && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
+ && (pLevel->notReady & pTerm->prereqAll)==0
+ ){
+ if( nLoop && (pTerm->wtFlags & TERM_LIKE)!=0 ){
+ pTerm->wtFlags |= TERM_LIKECOND;
+ }else{
+ pTerm->wtFlags |= TERM_CODED;
+ }
+ if( pTerm->iParent<0 ) break;
+ pTerm = &pTerm->pWC->a[pTerm->iParent];
+ pTerm->nChild--;
+ if( pTerm->nChild!=0 ) break;
+ nLoop++;
+ }
+}
+
+/*
+** Code an OP_Affinity opcode to apply the column affinity string zAff
+** to the n registers starting at base.
+**
+** As an optimization, SQLITE_AFF_BLOB entries (which are no-ops) at the
+** beginning and end of zAff are ignored. If all entries in zAff are
+** SQLITE_AFF_BLOB, then no code gets generated.
+**
+** This routine makes its own copy of zAff so that the caller is free
+** to modify zAff after this routine returns.
+*/
+static void codeApplyAffinity(Parse *pParse, int base, int n, char *zAff){
+ Vdbe *v = pParse->pVdbe;
+ if( zAff==0 ){
+ assert( pParse->db->mallocFailed );
+ return;
+ }
+ assert( v!=0 );
+
+ /* Adjust base and n to skip over SQLITE_AFF_BLOB entries at the beginning
+ ** and end of the affinity string.
+ */
+ while( n>0 && zAff[0]==SQLITE_AFF_BLOB ){
+ n--;
+ base++;
+ zAff++;
+ }
+ while( n>1 && zAff[n-1]==SQLITE_AFF_BLOB ){
+ n--;
+ }
+
+ /* Code the OP_Affinity opcode if there is anything left to do. */
+ if( n>0 ){
+ sqlite3VdbeAddOp2(v, OP_Affinity, base, n);
+ sqlite3VdbeChangeP4(v, -1, zAff, n);
+ sqlite3ExprCacheAffinityChange(pParse, base, n);
+ }
+}
+
+
+/*
+** Generate code for a single equality term of the WHERE clause. An equality
+** term can be either X=expr or X IN (...). pTerm is the term to be
+** coded.
+**
+** The current value for the constraint is left in register iReg.
+**
+** For a constraint of the form X=expr, the expression is evaluated and its
+** result is left on the stack. For constraints of the form X IN (...)
+** this routine sets up a loop that will iterate over all values of X.
+*/
+static int codeEqualityTerm(
+ Parse *pParse, /* The parsing context */
+ WhereTerm *pTerm, /* The term of the WHERE clause to be coded */
+ WhereLevel *pLevel, /* The level of the FROM clause we are working on */
+ int iEq, /* Index of the equality term within this level */
+ int bRev, /* True for reverse-order IN operations */
+ int iTarget /* Attempt to leave results in this register */
+){
+ Expr *pX = pTerm->pExpr;
+ Vdbe *v = pParse->pVdbe;
+ int iReg; /* Register holding results */
+
+ assert( iTarget>0 );
+ if( pX->op==TK_EQ || pX->op==TK_IS ){
+ iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);
+ }else if( pX->op==TK_ISNULL ){
+ iReg = iTarget;
+ sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
+#ifndef SQLITE_OMIT_SUBQUERY
+ }else{
+ int eType;
+ int iTab;
+ struct InLoop *pIn;
+ WhereLoop *pLoop = pLevel->pWLoop;
+
+ if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0
+ && pLoop->u.btree.pIndex!=0
+ && pLoop->u.btree.pIndex->aSortOrder[iEq]
+ ){
+ testcase( iEq==0 );
+ testcase( bRev );
+ bRev = !bRev;
+ }
+ assert( pX->op==TK_IN );
+ iReg = iTarget;
+ eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0);
+ if( eType==IN_INDEX_INDEX_DESC ){
+ testcase( bRev );
+ bRev = !bRev;
+ }
+ iTab = pX->iTable;
+ sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);
+ VdbeCoverageIf(v, bRev);
+ VdbeCoverageIf(v, !bRev);
+ assert( (pLoop->wsFlags & WHERE_MULTI_OR)==0 );
+ pLoop->wsFlags |= WHERE_IN_ABLE;
+ if( pLevel->u.in.nIn==0 ){
+ pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
+ }
+ pLevel->u.in.nIn++;
+ pLevel->u.in.aInLoop =
+ sqlite3DbReallocOrFree(pParse->db, pLevel->u.in.aInLoop,
+ sizeof(pLevel->u.in.aInLoop[0])*pLevel->u.in.nIn);
+ pIn = pLevel->u.in.aInLoop;
+ if( pIn ){
+ pIn += pLevel->u.in.nIn - 1;
+ pIn->iCur = iTab;
+ if( eType==IN_INDEX_ROWID ){
+ pIn->addrInTop = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iReg);
+ }else{
+ pIn->addrInTop = sqlite3VdbeAddOp3(v, OP_Column, iTab, 0, iReg);
+ }
+ pIn->eEndLoopOp = bRev ? OP_PrevIfOpen : OP_NextIfOpen;
+ sqlite3VdbeAddOp1(v, OP_IsNull, iReg); VdbeCoverage(v);
+ }else{
+ pLevel->u.in.nIn = 0;
+ }
+#endif
+ }
+ disableTerm(pLevel, pTerm);
+ return iReg;
+}
+
+/*
+** Generate code that will evaluate all == and IN constraints for an
+** index scan.
+**
+** For example, consider table t1(a,b,c,d,e,f) with index i1(a,b,c).
+** Suppose the WHERE clause is this: a==5 AND b IN (1,2,3) AND c>5 AND c<10
+** The index has as many as three equality constraints, but in this
+** example, the third "c" value is an inequality. So only two
+** constraints are coded. This routine will generate code to evaluate
+** a==5 and b IN (1,2,3). The current values for a and b will be stored
+** in consecutive registers and the index of the first register is returned.
+**
+** In the example above nEq==2. But this subroutine works for any value
+** of nEq including 0. If nEq==0, this routine is nearly a no-op.
+** The only thing it does is allocate the pLevel->iMem memory cell and
+** compute the affinity string.
+**
+** The nExtraReg parameter is 0 or 1. It is 0 if all WHERE clause constraints
+** are == or IN and are covered by the nEq. nExtraReg is 1 if there is
+** an inequality constraint (such as the "c>=5 AND c<10" in the example) that
+** occurs after the nEq quality constraints.
+**
+** This routine allocates a range of nEq+nExtraReg memory cells and returns
+** the index of the first memory cell in that range. The code that
+** calls this routine will use that memory range to store keys for
+** start and termination conditions of the loop.
+** key value of the loop. If one or more IN operators appear, then
+** this routine allocates an additional nEq memory cells for internal
+** use.
+**
+** Before returning, *pzAff is set to point to a buffer containing a
+** copy of the column affinity string of the index allocated using
+** sqlite3DbMalloc(). Except, entries in the copy of the string associated
+** with equality constraints that use BLOB or NONE affinity are set to
+** SQLITE_AFF_BLOB. This is to deal with SQL such as the following:
+**
+** CREATE TABLE t1(a TEXT PRIMARY KEY, b);
+** SELECT ... FROM t1 AS t2, t1 WHERE t1.a = t2.b;
+**
+** In the example above, the index on t1(a) has TEXT affinity. But since
+** the right hand side of the equality constraint (t2.b) has BLOB/NONE affinity,
+** no conversion should be attempted before using a t2.b value as part of
+** a key to search the index. Hence the first byte in the returned affinity
+** string in this example would be set to SQLITE_AFF_BLOB.
+*/
+static int codeAllEqualityTerms(
+ Parse *pParse, /* Parsing context */
+ WhereLevel *pLevel, /* Which nested loop of the FROM we are coding */
+ int bRev, /* Reverse the order of IN operators */
+ int nExtraReg, /* Number of extra registers to allocate */
+ char **pzAff /* OUT: Set to point to affinity string */
+){
+ u16 nEq; /* The number of == or IN constraints to code */
+ u16 nSkip; /* Number of left-most columns to skip */
+ Vdbe *v = pParse->pVdbe; /* The vm under construction */
+ Index *pIdx; /* The index being used for this loop */
+ WhereTerm *pTerm; /* A single constraint term */
+ WhereLoop *pLoop; /* The WhereLoop object */
+ int j; /* Loop counter */
+ int regBase; /* Base register */
+ int nReg; /* Number of registers to allocate */
+ char *zAff; /* Affinity string to return */
+
+ /* This module is only called on query plans that use an index. */
+ pLoop = pLevel->pWLoop;
+ assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );
+ nEq = pLoop->u.btree.nEq;
+ nSkip = pLoop->nSkip;
+ pIdx = pLoop->u.btree.pIndex;
+ assert( pIdx!=0 );
+
+ /* Figure out how many memory cells we will need then allocate them.
+ */
+ regBase = pParse->nMem + 1;
+ nReg = pLoop->u.btree.nEq + nExtraReg;
+ pParse->nMem += nReg;
+
+ zAff = sqlite3DbStrDup(pParse->db, sqlite3IndexAffinityStr(v, pIdx));
+ if( !zAff ){
+ pParse->db->mallocFailed = 1;
+ }
+
+ if( nSkip ){
+ int iIdxCur = pLevel->iIdxCur;
+ sqlite3VdbeAddOp1(v, (bRev?OP_Last:OP_Rewind), iIdxCur);
+ VdbeCoverageIf(v, bRev==0);
+ VdbeCoverageIf(v, bRev!=0);
+ VdbeComment((v, "begin skip-scan on %s", pIdx->zName));
+ j = sqlite3VdbeAddOp0(v, OP_Goto);
+ pLevel->addrSkip = sqlite3VdbeAddOp4Int(v, (bRev?OP_SeekLT:OP_SeekGT),
+ iIdxCur, 0, regBase, nSkip);
+ VdbeCoverageIf(v, bRev==0);
+ VdbeCoverageIf(v, bRev!=0);
+ sqlite3VdbeJumpHere(v, j);
+ for(j=0; j<nSkip; j++){
+ sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, j, regBase+j);
+ assert( pIdx->aiColumn[j]>=0 );
+ VdbeComment((v, "%s", pIdx->pTable->aCol[pIdx->aiColumn[j]].zName));
+ }
+ }
+
+ /* Evaluate the equality constraints
+ */
+ assert( zAff==0 || (int)strlen(zAff)>=nEq );
+ for(j=nSkip; j<nEq; j++){
+ int r1;
+ pTerm = pLoop->aLTerm[j];
+ assert( pTerm!=0 );
+ /* The following testcase is true for indices with redundant columns.
+ ** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */
+ testcase( (pTerm->wtFlags & TERM_CODED)!=0 );
+ testcase( pTerm->wtFlags & TERM_VIRTUAL );
+ r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, regBase+j);
+ if( r1!=regBase+j ){
+ if( nReg==1 ){
+ sqlite3ReleaseTempReg(pParse, regBase);
+ regBase = r1;
+ }else{
+ sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
+ }
+ }
+ testcase( pTerm->eOperator & WO_ISNULL );
+ testcase( pTerm->eOperator & WO_IN );
+ if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){
+ Expr *pRight = pTerm->pExpr->pRight;
+ if( (pTerm->wtFlags & TERM_IS)==0 && sqlite3ExprCanBeNull(pRight) ){
+ sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->addrBrk);
+ VdbeCoverage(v);
+ }
+ if( zAff ){
+ if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_BLOB ){
+ zAff[j] = SQLITE_AFF_BLOB;
+ }
+ if( sqlite3ExprNeedsNoAffinityChange(pRight, zAff[j]) ){
+ zAff[j] = SQLITE_AFF_BLOB;
+ }
+ }
+ }
+ }
+ *pzAff = zAff;
+ return regBase;
+}
+
+/*
+** If the most recently coded instruction is a constant range contraint
+** that originated from the LIKE optimization, then change the P3 to be
+** pLoop->iLikeRepCntr and set P5.
+**
+** The LIKE optimization trys to evaluate "x LIKE 'abc%'" as a range
+** expression: "x>='ABC' AND x<'abd'". But this requires that the range
+** scan loop run twice, once for strings and a second time for BLOBs.
+** The OP_String opcodes on the second pass convert the upper and lower
+** bound string contants to blobs. This routine makes the necessary changes
+** to the OP_String opcodes for that to happen.
+*/
+static void whereLikeOptimizationStringFixup(
+ Vdbe *v, /* prepared statement under construction */
+ WhereLevel *pLevel, /* The loop that contains the LIKE operator */
+ WhereTerm *pTerm /* The upper or lower bound just coded */
+){
+ if( pTerm->wtFlags & TERM_LIKEOPT ){
+ VdbeOp *pOp;
+ assert( pLevel->iLikeRepCntr>0 );
+ pOp = sqlite3VdbeGetOp(v, -1);
+ assert( pOp!=0 );
+ assert( pOp->opcode==OP_String8
+ || pTerm->pWC->pWInfo->pParse->db->mallocFailed );
+ pOp->p3 = pLevel->iLikeRepCntr;
+ pOp->p5 = 1;
+ }
+}
+
+
+/*
+** Generate code for the start of the iLevel-th loop in the WHERE clause
+** implementation described by pWInfo.
+*/
+Bitmask sqlite3WhereCodeOneLoopStart(
+ WhereInfo *pWInfo, /* Complete information about the WHERE clause */
+ int iLevel, /* Which level of pWInfo->a[] should be coded */
+ Bitmask notReady /* Which tables are currently available */
+){
+ int j, k; /* Loop counters */
+ int iCur; /* The VDBE cursor for the table */
+ int addrNxt; /* Where to jump to continue with the next IN case */
+ int omitTable; /* True if we use the index only */
+ int bRev; /* True if we need to scan in reverse order */
+ WhereLevel *pLevel; /* The where level to be coded */
+ WhereLoop *pLoop; /* The WhereLoop object being coded */
+ WhereClause *pWC; /* Decomposition of the entire WHERE clause */
+ WhereTerm *pTerm; /* A WHERE clause term */
+ Parse *pParse; /* Parsing context */
+ sqlite3 *db; /* Database connection */
+ Vdbe *v; /* The prepared stmt under constructions */
+ struct SrcList_item *pTabItem; /* FROM clause term being coded */
+ int addrBrk; /* Jump here to break out of the loop */
+ int addrCont; /* Jump here to continue with next cycle */
+ int iRowidReg = 0; /* Rowid is stored in this register, if not zero */
+ int iReleaseReg = 0; /* Temp register to free before returning */
+
+ pParse = pWInfo->pParse;
+ v = pParse->pVdbe;
+ pWC = &pWInfo->sWC;
+ db = pParse->db;
+ pLevel = &pWInfo->a[iLevel];
+ pLoop = pLevel->pWLoop;
+ pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
+ iCur = pTabItem->iCursor;
+ pLevel->notReady = notReady & ~sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur);
+ bRev = (pWInfo->revMask>>iLevel)&1;
+ omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0
+ && (pWInfo->wctrlFlags & WHERE_FORCE_TABLE)==0;
+ 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.
+ ** Jump to cont to go immediately to the next iteration of the
+ ** loop.
+ **
+ ** When there is an IN operator, we also have a "addrNxt" label that
+ ** means to continue with the next IN value combination. When
+ ** there are no IN operators in the constraints, the "addrNxt" label
+ ** is the same as "addrBrk".
+ */
+ addrBrk = pLevel->addrBrk = pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
+ addrCont = pLevel->addrCont = sqlite3VdbeMakeLabel(v);
+
+ /* If this is the right table of a LEFT OUTER JOIN, allocate and
+ ** initialize a memory cell that records if this table matches any
+ ** row of the left table of the join.
+ */
+ if( pLevel->iFrom>0 && (pTabItem[0].jointype & JT_LEFT)!=0 ){
+ pLevel->iLeftJoin = ++pParse->nMem;
+ sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
+ VdbeComment((v, "init LEFT JOIN no-match flag"));
+ }
+
+ /* Special case of a FROM clause subquery implemented as a co-routine */
+ if( pTabItem->viaCoroutine ){
+ int regYield = pTabItem->regReturn;
+ sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);
+ pLevel->p2 = sqlite3VdbeAddOp2(v, OP_Yield, regYield, addrBrk);
+ VdbeCoverage(v);
+ VdbeComment((v, "next row of \"%s\"", pTabItem->pTab->zName));
+ pLevel->op = OP_Goto;
+ }else
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+ if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
+ /* Case 1: The table is a virtual-table. Use the VFilter and VNext
+ ** to access the data.
+ */
+ int iReg; /* P3 Value for OP_VFilter */
+ int addrNotFound;
+ int nConstraint = pLoop->nLTerm;
+
+ sqlite3ExprCachePush(pParse);
+ iReg = sqlite3GetTempRange(pParse, nConstraint+2);
+ addrNotFound = pLevel->addrBrk;
+ for(j=0; j<nConstraint; j++){
+ int iTarget = iReg+j+2;
+ pTerm = pLoop->aLTerm[j];
+ if( pTerm==0 ) continue;
+ if( pTerm->eOperator & WO_IN ){
+ codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, iTarget);
+ addrNotFound = pLevel->addrNxt;
+ }else{
+ sqlite3ExprCode(pParse, pTerm->pExpr->pRight, iTarget);
+ }
+ }
+ sqlite3VdbeAddOp2(v, OP_Integer, pLoop->u.vtab.idxNum, iReg);
+ sqlite3VdbeAddOp2(v, OP_Integer, nConstraint, iReg+1);
+ sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg,
+ pLoop->u.vtab.idxStr,
+ pLoop->u.vtab.needFree ? P4_MPRINTF : P4_STATIC);
+ VdbeCoverage(v);
+ pLoop->u.vtab.needFree = 0;
+ for(j=0; j<nConstraint && j<16; j++){
+ if( (pLoop->u.vtab.omitMask>>j)&1 ){
+ disableTerm(pLevel, pLoop->aLTerm[j]);
+ }
+ }
+ pLevel->op = OP_VNext;
+ pLevel->p1 = iCur;
+ pLevel->p2 = sqlite3VdbeCurrentAddr(v);
+ sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
+ sqlite3ExprCachePop(pParse);
+ }else
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+ if( (pLoop->wsFlags & WHERE_IPK)!=0
+ && (pLoop->wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_EQ))!=0
+ ){
+ /* Case 2: We can directly reference a single row using an
+ ** equality comparison against the ROWID field. Or
+ ** we reference multiple rows using a "rowid IN (...)"
+ ** construct.
+ */
+ assert( pLoop->u.btree.nEq==1 );
+ pTerm = pLoop->aLTerm[0];
+ assert( pTerm!=0 );
+ assert( pTerm->pExpr!=0 );
+ assert( omitTable==0 );
+ testcase( pTerm->wtFlags & TERM_VIRTUAL );
+ iReleaseReg = ++pParse->nMem;
+ iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, bRev, iReleaseReg);
+ if( iRowidReg!=iReleaseReg ) sqlite3ReleaseTempReg(pParse, iReleaseReg);
+ addrNxt = pLevel->addrNxt;
+ sqlite3VdbeAddOp2(v, OP_MustBeInt, iRowidReg, addrNxt); VdbeCoverage(v);
+ sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addrNxt, iRowidReg);
+ VdbeCoverage(v);
+ sqlite3ExprCacheAffinityChange(pParse, iRowidReg, 1);
+ sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
+ VdbeComment((v, "pk"));
+ pLevel->op = OP_Noop;
+ }else if( (pLoop->wsFlags & WHERE_IPK)!=0
+ && (pLoop->wsFlags & WHERE_COLUMN_RANGE)!=0
+ ){
+ /* Case 3: We have an inequality comparison against the ROWID field.
+ */
+ int testOp = OP_Noop;
+ int start;
+ int memEndValue = 0;
+ WhereTerm *pStart, *pEnd;
+
+ assert( omitTable==0 );
+ j = 0;
+ pStart = pEnd = 0;
+ if( pLoop->wsFlags & WHERE_BTM_LIMIT ) pStart = pLoop->aLTerm[j++];
+ if( pLoop->wsFlags & WHERE_TOP_LIMIT ) pEnd = pLoop->aLTerm[j++];
+ assert( pStart!=0 || pEnd!=0 );
+ if( bRev ){
+ pTerm = pStart;
+ pStart = pEnd;
+ pEnd = pTerm;
+ }
+ if( pStart ){
+ Expr *pX; /* The expression that defines the start bound */
+ int r1, rTemp; /* Registers for holding the start boundary */
+
+ /* The following constant maps TK_xx codes into corresponding
+ ** seek opcodes. It depends on a particular ordering of TK_xx
+ */
+ const u8 aMoveOp[] = {
+ /* TK_GT */ OP_SeekGT,
+ /* TK_LE */ OP_SeekLE,
+ /* TK_LT */ OP_SeekLT,
+ /* TK_GE */ OP_SeekGE
+ };
+ assert( TK_LE==TK_GT+1 ); /* Make sure the ordering.. */
+ assert( TK_LT==TK_GT+2 ); /* ... of the TK_xx values... */
+ assert( TK_GE==TK_GT+3 ); /* ... is correcct. */
+
+ assert( (pStart->wtFlags & TERM_VNULL)==0 );
+ testcase( pStart->wtFlags & TERM_VIRTUAL );
+ pX = pStart->pExpr;
+ assert( pX!=0 );
+ testcase( pStart->leftCursor!=iCur ); /* transitive constraints */
+ r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);
+ sqlite3VdbeAddOp3(v, aMoveOp[pX->op-TK_GT], iCur, addrBrk, r1);
+ VdbeComment((v, "pk"));
+ VdbeCoverageIf(v, pX->op==TK_GT);
+ VdbeCoverageIf(v, pX->op==TK_LE);
+ VdbeCoverageIf(v, pX->op==TK_LT);
+ VdbeCoverageIf(v, pX->op==TK_GE);
+ sqlite3ExprCacheAffinityChange(pParse, r1, 1);
+ sqlite3ReleaseTempReg(pParse, rTemp);
+ disableTerm(pLevel, pStart);
+ }else{
+ sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, addrBrk);
+ VdbeCoverageIf(v, bRev==0);
+ VdbeCoverageIf(v, bRev!=0);
+ }
+ if( pEnd ){
+ Expr *pX;
+ pX = pEnd->pExpr;
+ assert( pX!=0 );
+ assert( (pEnd->wtFlags & TERM_VNULL)==0 );
+ testcase( pEnd->leftCursor!=iCur ); /* Transitive constraints */
+ testcase( pEnd->wtFlags & TERM_VIRTUAL );
+ memEndValue = ++pParse->nMem;
+ sqlite3ExprCode(pParse, pX->pRight, memEndValue);
+ if( pX->op==TK_LT || pX->op==TK_GT ){
+ testOp = bRev ? OP_Le : OP_Ge;
+ }else{
+ testOp = bRev ? OP_Lt : OP_Gt;
+ }
+ disableTerm(pLevel, pEnd);
+ }
+ start = sqlite3VdbeCurrentAddr(v);
+ pLevel->op = bRev ? OP_Prev : OP_Next;
+ pLevel->p1 = iCur;
+ pLevel->p2 = start;
+ assert( pLevel->p5==0 );
+ if( testOp!=OP_Noop ){
+ iRowidReg = ++pParse->nMem;
+ sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);
+ sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
+ sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg);
+ VdbeCoverageIf(v, testOp==OP_Le);
+ VdbeCoverageIf(v, testOp==OP_Lt);
+ VdbeCoverageIf(v, testOp==OP_Ge);
+ VdbeCoverageIf(v, testOp==OP_Gt);
+ sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
+ }
+ }else if( pLoop->wsFlags & WHERE_INDEXED ){
+ /* Case 4: A scan using an index.
+ **
+ ** The WHERE clause may contain zero or more equality
+ ** terms ("==" or "IN" operators) that refer to the N
+ ** left-most columns of the index. It may also contain
+ ** inequality constraints (>, <, >= or <=) on the indexed
+ ** column that immediately follows the N equalities. Only
+ ** the right-most column can be an inequality - the rest must
+ ** use the "==" and "IN" operators. For example, if the
+ ** index is on (x,y,z), then the following clauses are all
+ ** optimized:
+ **
+ ** x=5
+ ** x=5 AND y=10
+ ** x=5 AND y<10
+ ** x=5 AND y>5 AND y<10
+ ** x=5 AND y=5 AND z<=10
+ **
+ ** The z<10 term of the following cannot be used, only
+ ** the x=5 term:
+ **
+ ** x=5 AND z<10
+ **
+ ** N may be zero if there are inequality constraints.
+ ** If there are no inequality constraints, then N is at
+ ** least one.
+ **
+ ** This case is also used when there are no WHERE clause
+ ** constraints but an index is selected anyway, in order
+ ** to force the output order to conform to an ORDER BY.
+ */
+ static const u8 aStartOp[] = {
+ 0,
+ 0,
+ OP_Rewind, /* 2: (!start_constraints && startEq && !bRev) */
+ OP_Last, /* 3: (!start_constraints && startEq && bRev) */
+ OP_SeekGT, /* 4: (start_constraints && !startEq && !bRev) */
+ OP_SeekLT, /* 5: (start_constraints && !startEq && bRev) */
+ OP_SeekGE, /* 6: (start_constraints && startEq && !bRev) */
+ OP_SeekLE /* 7: (start_constraints && startEq && bRev) */
+ };
+ static const u8 aEndOp[] = {
+ OP_IdxGE, /* 0: (end_constraints && !bRev && !endEq) */
+ OP_IdxGT, /* 1: (end_constraints && !bRev && endEq) */
+ OP_IdxLE, /* 2: (end_constraints && bRev && !endEq) */
+ OP_IdxLT, /* 3: (end_constraints && bRev && endEq) */
+ };
+ u16 nEq = pLoop->u.btree.nEq; /* Number of == or IN terms */
+ int regBase; /* Base register holding constraint values */
+ WhereTerm *pRangeStart = 0; /* Inequality constraint at range start */
+ WhereTerm *pRangeEnd = 0; /* Inequality constraint at range end */
+ int startEq; /* True if range start uses ==, >= or <= */
+ int endEq; /* True if range end uses ==, >= or <= */
+ int start_constraints; /* Start of range is constrained */
+ int nConstraint; /* Number of constraint terms */
+ Index *pIdx; /* The index we will be using */
+ int iIdxCur; /* The VDBE cursor for the index */
+ int nExtraReg = 0; /* Number of extra registers needed */
+ int op; /* Instruction opcode */
+ char *zStartAff; /* Affinity for start of range constraint */
+ char cEndAff = 0; /* Affinity for end of range constraint */
+ u8 bSeekPastNull = 0; /* True to seek past initial nulls */
+ u8 bStopAtNull = 0; /* Add condition to terminate at NULLs */
+
+ pIdx = pLoop->u.btree.pIndex;
+ iIdxCur = pLevel->iIdxCur;
+ assert( nEq>=pLoop->nSkip );
+
+ /* If this loop satisfies a sort order (pOrderBy) request that
+ ** was passed to this function to implement a "SELECT min(x) ..."
+ ** query, then the caller will only allow the loop to run for
+ ** a single iteration. This means that the first row returned
+ ** should not have a NULL value stored in 'x'. If column 'x' is
+ ** the first one after the nEq equality constraints in the index,
+ ** this requires some special handling.
+ */
+ assert( pWInfo->pOrderBy==0
+ || pWInfo->pOrderBy->nExpr==1
+ || (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0 );
+ if( (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)!=0
+ && pWInfo->nOBSat>0
+ && (pIdx->nKeyCol>nEq)
+ ){
+ assert( pLoop->nSkip==0 );
+ bSeekPastNull = 1;
+ nExtraReg = 1;
+ }
+
+ /* Find any inequality constraint terms for the start and end
+ ** of the range.
+ */
+ j = nEq;
+ if( pLoop->wsFlags & WHERE_BTM_LIMIT ){
+ pRangeStart = pLoop->aLTerm[j++];
+ nExtraReg = 1;
+ /* Like optimization range constraints always occur in pairs */
+ assert( (pRangeStart->wtFlags & TERM_LIKEOPT)==0 ||
+ (pLoop->wsFlags & WHERE_TOP_LIMIT)!=0 );
+ }
+ if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
+ pRangeEnd = pLoop->aLTerm[j++];
+ nExtraReg = 1;
+ if( (pRangeEnd->wtFlags & TERM_LIKEOPT)!=0 ){
+ assert( pRangeStart!=0 ); /* LIKE opt constraints */
+ assert( pRangeStart->wtFlags & TERM_LIKEOPT ); /* occur in pairs */
+ pLevel->iLikeRepCntr = ++pParse->nMem;
+ testcase( bRev );
+ testcase( pIdx->aSortOrder[nEq]==SQLITE_SO_DESC );
+ sqlite3VdbeAddOp2(v, OP_Integer,
+ bRev ^ (pIdx->aSortOrder[nEq]==SQLITE_SO_DESC),
+ pLevel->iLikeRepCntr);
+ VdbeComment((v, "LIKE loop counter"));
+ pLevel->addrLikeRep = sqlite3VdbeCurrentAddr(v);
+ }
+ if( pRangeStart==0
+ && (j = pIdx->aiColumn[nEq])>=0
+ && pIdx->pTable->aCol[j].notNull==0
+ ){
+ bSeekPastNull = 1;
+ }
+ }
+ assert( pRangeEnd==0 || (pRangeEnd->wtFlags & TERM_VNULL)==0 );
+
+ /* Generate code to evaluate all constraint terms using == or IN
+ ** and store the values of those terms in an array of registers
+ ** starting at regBase.
+ */
+ regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);
+ assert( zStartAff==0 || sqlite3Strlen30(zStartAff)>=nEq );
+ if( zStartAff ) cEndAff = zStartAff[nEq];
+ addrNxt = pLevel->addrNxt;
+
+ /* If we are doing a reverse order scan on an ascending index, or
+ ** a forward order scan on a descending index, interchange the
+ ** start and end terms (pRangeStart and pRangeEnd).
+ */
+ if( (nEq<pIdx->nKeyCol && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC))
+ || (bRev && pIdx->nKeyCol==nEq)
+ ){
+ SWAP(WhereTerm *, pRangeEnd, pRangeStart);
+ SWAP(u8, bSeekPastNull, bStopAtNull);
+ }
+
+ testcase( pRangeStart && (pRangeStart->eOperator & WO_LE)!=0 );
+ testcase( pRangeStart && (pRangeStart->eOperator & WO_GE)!=0 );
+ testcase( pRangeEnd && (pRangeEnd->eOperator & WO_LE)!=0 );
+ testcase( pRangeEnd && (pRangeEnd->eOperator & WO_GE)!=0 );
+ startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
+ endEq = !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
+ start_constraints = pRangeStart || nEq>0;
+
+ /* Seek the index cursor to the start of the range. */
+ nConstraint = nEq;
+ if( pRangeStart ){
+ Expr *pRight = pRangeStart->pExpr->pRight;
+ sqlite3ExprCode(pParse, pRight, regBase+nEq);
+ whereLikeOptimizationStringFixup(v, pLevel, pRangeStart);
+ if( (pRangeStart->wtFlags & TERM_VNULL)==0
+ && sqlite3ExprCanBeNull(pRight)
+ ){
+ sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
+ VdbeCoverage(v);
+ }
+ if( zStartAff ){
+ if( sqlite3CompareAffinity(pRight, zStartAff[nEq])==SQLITE_AFF_BLOB){
+ /* Since the comparison is to be performed with no conversions
+ ** applied to the operands, set the affinity to apply to pRight to
+ ** SQLITE_AFF_BLOB. */
+ zStartAff[nEq] = SQLITE_AFF_BLOB;
+ }
+ if( sqlite3ExprNeedsNoAffinityChange(pRight, zStartAff[nEq]) ){
+ zStartAff[nEq] = SQLITE_AFF_BLOB;
+ }
+ }
+ nConstraint++;
+ testcase( pRangeStart->wtFlags & TERM_VIRTUAL );
+ }else if( bSeekPastNull ){
+ sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
+ nConstraint++;
+ startEq = 0;
+ start_constraints = 1;
+ }
+ codeApplyAffinity(pParse, regBase, nConstraint - bSeekPastNull, zStartAff);
+ op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];
+ assert( op!=0 );
+ sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
+ VdbeCoverage(v);
+ VdbeCoverageIf(v, op==OP_Rewind); testcase( op==OP_Rewind );
+ VdbeCoverageIf(v, op==OP_Last); testcase( op==OP_Last );
+ VdbeCoverageIf(v, op==OP_SeekGT); testcase( op==OP_SeekGT );
+ VdbeCoverageIf(v, op==OP_SeekGE); testcase( op==OP_SeekGE );
+ VdbeCoverageIf(v, op==OP_SeekLE); testcase( op==OP_SeekLE );
+ VdbeCoverageIf(v, op==OP_SeekLT); testcase( op==OP_SeekLT );
+
+ /* Load the value for the inequality constraint at the end of the
+ ** range (if any).
+ */
+ nConstraint = nEq;
+ if( pRangeEnd ){
+ Expr *pRight = pRangeEnd->pExpr->pRight;
+ sqlite3ExprCacheRemove(pParse, regBase+nEq, 1);
+ sqlite3ExprCode(pParse, pRight, regBase+nEq);
+ whereLikeOptimizationStringFixup(v, pLevel, pRangeEnd);
+ if( (pRangeEnd->wtFlags & TERM_VNULL)==0
+ && sqlite3ExprCanBeNull(pRight)
+ ){
+ sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
+ VdbeCoverage(v);
+ }
+ if( sqlite3CompareAffinity(pRight, cEndAff)!=SQLITE_AFF_BLOB
+ && !sqlite3ExprNeedsNoAffinityChange(pRight, cEndAff)
+ ){
+ codeApplyAffinity(pParse, regBase+nEq, 1, &cEndAff);
+ }
+ nConstraint++;
+ testcase( pRangeEnd->wtFlags & TERM_VIRTUAL );
+ }else if( bStopAtNull ){
+ sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
+ endEq = 0;
+ nConstraint++;
+ }
+ sqlite3DbFree(db, zStartAff);
+
+ /* Top of the loop body */
+ pLevel->p2 = sqlite3VdbeCurrentAddr(v);
+
+ /* Check if the index cursor is past the end of the range. */
+ if( nConstraint ){
+ op = aEndOp[bRev*2 + endEq];
+ sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
+ testcase( op==OP_IdxGT ); VdbeCoverageIf(v, op==OP_IdxGT );
+ testcase( op==OP_IdxGE ); VdbeCoverageIf(v, op==OP_IdxGE );
+ testcase( op==OP_IdxLT ); VdbeCoverageIf(v, op==OP_IdxLT );
+ testcase( op==OP_IdxLE ); VdbeCoverageIf(v, op==OP_IdxLE );
+ }
+
+ /* Seek the table cursor, if required */
+ disableTerm(pLevel, pRangeStart);
+ disableTerm(pLevel, pRangeEnd);
+ if( omitTable ){
+ /* pIdx is a covering index. No need to access the main table. */
+ }else if( HasRowid(pIdx->pTable) ){
+ iRowidReg = ++pParse->nMem;
+ sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
+ sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
+ sqlite3VdbeAddOp2(v, OP_Seek, iCur, iRowidReg); /* Deferred seek */
+ }else if( iCur!=iIdxCur ){
+ Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
+ iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);
+ for(j=0; j<pPk->nKeyCol; j++){
+ k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
+ sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);
+ }
+ sqlite3VdbeAddOp4Int(v, OP_NotFound, iCur, addrCont,
+ iRowidReg, pPk->nKeyCol); VdbeCoverage(v);
+ }
+
+ /* Record the instruction used to terminate the loop. Disable
+ ** WHERE clause terms made redundant by the index range scan.
+ */
+ if( pLoop->wsFlags & WHERE_ONEROW ){
+ pLevel->op = OP_Noop;
+ }else if( bRev ){
+ pLevel->op = OP_Prev;
+ }else{
+ pLevel->op = OP_Next;
+ }
+ pLevel->p1 = iIdxCur;
+ pLevel->p3 = (pLoop->wsFlags&WHERE_UNQ_WANTED)!=0 ? 1:0;
+ if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){
+ pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
+ }else{
+ assert( pLevel->p5==0 );
+ }
+ }else
+
+#ifndef SQLITE_OMIT_OR_OPTIMIZATION
+ if( pLoop->wsFlags & WHERE_MULTI_OR ){
+ /* Case 5: Two or more separately indexed terms connected by OR
+ **
+ ** Example:
+ **
+ ** CREATE TABLE t1(a,b,c,d);
+ ** CREATE INDEX i1 ON t1(a);
+ ** CREATE INDEX i2 ON t1(b);
+ ** CREATE INDEX i3 ON t1(c);
+ **
+ ** SELECT * FROM t1 WHERE a=5 OR b=7 OR (c=11 AND d=13)
+ **
+ ** In the example, there are three indexed terms connected by OR.
+ ** The top of the loop looks like this:
+ **
+ ** Null 1 # Zero the rowset in reg 1
+ **
+ ** Then, for each indexed term, the following. The arguments to
+ ** RowSetTest are such that the rowid of the current row is inserted
+ ** into the RowSet. If it is already present, control skips the
+ ** Gosub opcode and jumps straight to the code generated by WhereEnd().
+ **
+ ** sqlite3WhereBegin(<term>)
+ ** RowSetTest # Insert rowid into rowset
+ ** Gosub 2 A
+ ** sqlite3WhereEnd()
+ **
+ ** Following the above, code to terminate the loop. Label A, the target
+ ** of the Gosub above, jumps to the instruction right after the Goto.
+ **
+ ** Null 1 # Zero the rowset in reg 1
+ ** Goto B # The loop is finished.
+ **
+ ** A: <loop body> # Return data, whatever.
+ **
+ ** Return 2 # Jump back to the Gosub
+ **
+ ** B: <after the loop>
+ **
+ ** Added 2014-05-26: If the table is a WITHOUT ROWID table, then
+ ** use an ephemeral index instead of a RowSet to record the primary
+ ** keys of the rows we have already seen.
+ **
+ */
+ WhereClause *pOrWc; /* The OR-clause broken out into subterms */
+ SrcList *pOrTab; /* Shortened table list or OR-clause generation */
+ Index *pCov = 0; /* Potential covering index (or NULL) */
+ int iCovCur = pParse->nTab++; /* Cursor used for index scans (if any) */
+
+ int regReturn = ++pParse->nMem; /* Register used with OP_Gosub */
+ int regRowset = 0; /* Register for RowSet object */
+ int regRowid = 0; /* Register holding rowid */
+ int iLoopBody = sqlite3VdbeMakeLabel(v); /* Start of loop body */
+ int iRetInit; /* Address of regReturn init */
+ int untestedTerms = 0; /* Some terms not completely tested */
+ int ii; /* Loop counter */
+ u16 wctrlFlags; /* Flags for sub-WHERE clause */
+ Expr *pAndExpr = 0; /* An ".. AND (...)" expression */
+ Table *pTab = pTabItem->pTab;
+
+ pTerm = pLoop->aLTerm[0];
+ assert( pTerm!=0 );
+ assert( pTerm->eOperator & WO_OR );
+ assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
+ pOrWc = &pTerm->u.pOrInfo->wc;
+ pLevel->op = OP_Return;
+ pLevel->p1 = regReturn;
+
+ /* Set up a new SrcList in pOrTab containing the table being scanned
+ ** by this loop in the a[0] slot and all notReady tables in a[1..] slots.
+ ** This becomes the SrcList in the recursive call to sqlite3WhereBegin().
+ */
+ if( pWInfo->nLevel>1 ){
+ int nNotReady; /* The number of notReady tables */
+ struct SrcList_item *origSrc; /* Original list of tables */
+ nNotReady = pWInfo->nLevel - iLevel - 1;
+ pOrTab = sqlite3StackAllocRaw(db,
+ sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0]));
+ if( pOrTab==0 ) return notReady;
+ pOrTab->nAlloc = (u8)(nNotReady + 1);
+ pOrTab->nSrc = pOrTab->nAlloc;
+ memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem));
+ origSrc = pWInfo->pTabList->a;
+ for(k=1; k<=nNotReady; k++){
+ memcpy(&pOrTab->a[k], &origSrc[pLevel[k].iFrom], sizeof(pOrTab->a[k]));
+ }
+ }else{
+ pOrTab = pWInfo->pTabList;
+ }
+
+ /* Initialize the rowset register to contain NULL. An SQL NULL is
+ ** equivalent to an empty rowset. Or, create an ephemeral index
+ ** capable of holding primary keys in the case of a WITHOUT ROWID.
+ **
+ ** Also initialize regReturn to contain the address of the instruction
+ ** immediately following the OP_Return at the bottom of the loop. This
+ ** is required in a few obscure LEFT JOIN cases where control jumps
+ ** over the top of the loop into the body of it. In this case the
+ ** correct response for the end-of-loop code (the OP_Return) is to
+ ** fall through to the next instruction, just as an OP_Next does if
+ ** called on an uninitialized cursor.
+ */
+ if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
+ if( HasRowid(pTab) ){
+ regRowset = ++pParse->nMem;
+ sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);
+ }else{
+ Index *pPk = sqlite3PrimaryKeyIndex(pTab);
+ regRowset = pParse->nTab++;
+ sqlite3VdbeAddOp2(v, OP_OpenEphemeral, regRowset, pPk->nKeyCol);
+ sqlite3VdbeSetP4KeyInfo(pParse, pPk);
+ }
+ regRowid = ++pParse->nMem;
+ }
+ iRetInit = sqlite3VdbeAddOp2(v, OP_Integer, 0, regReturn);
+
+ /* If the original WHERE clause is z of the form: (x1 OR x2 OR ...) AND y
+ ** Then for every term xN, evaluate as the subexpression: xN AND z
+ ** That way, terms in y that are factored into the disjunction will
+ ** be picked up by the recursive calls to sqlite3WhereBegin() below.
+ **
+ ** Actually, each subexpression is converted to "xN AND w" where w is
+ ** the "interesting" terms of z - terms that did not originate in the
+ ** ON or USING clause of a LEFT JOIN, and terms that are usable as
+ ** indices.
+ **
+ ** This optimization also only applies if the (x1 OR x2 OR ...) term
+ ** is not contained in the ON clause of a LEFT JOIN.
+ ** See ticket http://www.sqlite.org/src/info/f2369304e4
+ */
+ if( pWC->nTerm>1 ){
+ int iTerm;
+ for(iTerm=0; iTerm<pWC->nTerm; iTerm++){
+ Expr *pExpr = pWC->a[iTerm].pExpr;
+ if( &pWC->a[iTerm] == pTerm ) continue;
+ if( ExprHasProperty(pExpr, EP_FromJoin) ) continue;
+ if( (pWC->a[iTerm].wtFlags & TERM_VIRTUAL)!=0 ) continue;
+ if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
+ testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
+ pExpr = sqlite3ExprDup(db, pExpr, 0);
+ pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr);
+ }
+ if( pAndExpr ){
+ pAndExpr = sqlite3PExpr(pParse, TK_AND, 0, pAndExpr, 0);
+ }
+ }
+
+ /* Run a separate WHERE clause for each term of the OR clause. After
+ ** eliminating duplicates from other WHERE clauses, the action for each
+ ** sub-WHERE clause is to to invoke the main loop body as a subroutine.
+ */
+ wctrlFlags = WHERE_OMIT_OPEN_CLOSE
+ | WHERE_FORCE_TABLE
+ | WHERE_ONETABLE_ONLY
+ | WHERE_NO_AUTOINDEX;
+ for(ii=0; ii<pOrWc->nTerm; ii++){
+ WhereTerm *pOrTerm = &pOrWc->a[ii];
+ if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){
+ WhereInfo *pSubWInfo; /* Info for single OR-term scan */
+ Expr *pOrExpr = pOrTerm->pExpr; /* Current OR clause term */
+ int j1 = 0; /* Address of jump operation */
+ if( pAndExpr && !ExprHasProperty(pOrExpr, EP_FromJoin) ){
+ pAndExpr->pLeft = pOrExpr;
+ pOrExpr = pAndExpr;
+ }
+ /* Loop through table entries that match term pOrTerm. */
+ WHERETRACE(0xffff, ("Subplan for OR-clause:\n"));
+ pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0,
+ wctrlFlags, iCovCur);
+ assert( pSubWInfo || pParse->nErr || db->mallocFailed );
+ if( pSubWInfo ){
+ WhereLoop *pSubLoop;
+ int addrExplain = sqlite3WhereExplainOneScan(
+ pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0
+ );
+ sqlite3WhereAddScanStatus(v, pOrTab, &pSubWInfo->a[0], addrExplain);
+
+ /* This is the sub-WHERE clause body. First skip over
+ ** duplicate rows from prior sub-WHERE clauses, and record the
+ ** rowid (or PRIMARY KEY) for the current row so that the same
+ ** row will be skipped in subsequent sub-WHERE clauses.
+ */
+ if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
+ int r;
+ int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
+ if( HasRowid(pTab) ){
+ r = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, regRowid, 0);
+ j1 = sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, 0, r,iSet);
+ VdbeCoverage(v);
+ }else{
+ Index *pPk = sqlite3PrimaryKeyIndex(pTab);
+ int nPk = pPk->nKeyCol;
+ int iPk;
+
+ /* Read the PK into an array of temp registers. */
+ r = sqlite3GetTempRange(pParse, nPk);
+ for(iPk=0; iPk<nPk; iPk++){
+ int iCol = pPk->aiColumn[iPk];
+ sqlite3ExprCodeGetColumn(pParse, pTab, iCol, iCur, r+iPk, 0);
+ }
+
+ /* Check if the temp table already contains this key. If so,
+ ** the row has already been included in the result set and
+ ** can be ignored (by jumping past the Gosub below). Otherwise,
+ ** insert the key into the temp table and proceed with processing
+ ** the row.
+ **
+ ** Use some of the same optimizations as OP_RowSetTest: If iSet
+ ** is zero, assume that the key cannot already be present in
+ ** the temp table. And if iSet is -1, assume that there is no
+ ** need to insert the key into the temp table, as it will never
+ ** be tested for. */
+ if( iSet ){
+ j1 = sqlite3VdbeAddOp4Int(v, OP_Found, regRowset, 0, r, nPk);
+ VdbeCoverage(v);
+ }
+ if( iSet>=0 ){
+ sqlite3VdbeAddOp3(v, OP_MakeRecord, r, nPk, regRowid);
+ sqlite3VdbeAddOp3(v, OP_IdxInsert, regRowset, regRowid, 0);
+ if( iSet ) sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
+ }
+
+ /* Release the array of temp registers */
+ sqlite3ReleaseTempRange(pParse, r, nPk);
+ }
+ }
+
+ /* Invoke the main loop body as a subroutine */
+ sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody);
+
+ /* Jump here (skipping the main loop body subroutine) if the
+ ** current sub-WHERE row is a duplicate from prior sub-WHEREs. */
+ if( j1 ) sqlite3VdbeJumpHere(v, j1);
+
+ /* The pSubWInfo->untestedTerms flag means that this OR term
+ ** contained one or more AND term from a notReady table. The
+ ** terms from the notReady table could not be tested and will
+ ** need to be tested later.
+ */
+ if( pSubWInfo->untestedTerms ) untestedTerms = 1;
+
+ /* If all of the OR-connected terms are optimized using the same
+ ** index, and the index is opened using the same cursor number
+ ** by each call to sqlite3WhereBegin() made by this loop, it may
+ ** be possible to use that index as a covering index.
+ **
+ ** If the call to sqlite3WhereBegin() above resulted in a scan that
+ ** uses an index, and this is either the first OR-connected term
+ ** processed or the index is the same as that used by all previous
+ ** terms, set pCov to the candidate covering index. Otherwise, set
+ ** pCov to NULL to indicate that no candidate covering index will
+ ** be available.
+ */
+ pSubLoop = pSubWInfo->a[0].pWLoop;
+ assert( (pSubLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
+ if( (pSubLoop->wsFlags & WHERE_INDEXED)!=0
+ && (ii==0 || pSubLoop->u.btree.pIndex==pCov)
+ && (HasRowid(pTab) || !IsPrimaryKeyIndex(pSubLoop->u.btree.pIndex))
+ ){
+ assert( pSubWInfo->a[0].iIdxCur==iCovCur );
+ pCov = pSubLoop->u.btree.pIndex;
+ wctrlFlags |= WHERE_REOPEN_IDX;
+ }else{
+ pCov = 0;
+ }
+
+ /* Finish the loop through table entries that match term pOrTerm. */
+ sqlite3WhereEnd(pSubWInfo);
+ }
+ }
+ }
+ pLevel->u.pCovidx = pCov;
+ if( pCov ) pLevel->iIdxCur = iCovCur;
+ if( pAndExpr ){
+ pAndExpr->pLeft = 0;
+ sqlite3ExprDelete(db, pAndExpr);
+ }
+ sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));
+ sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrBrk);
+ sqlite3VdbeResolveLabel(v, iLoopBody);
+
+ if( pWInfo->nLevel>1 ) sqlite3StackFree(db, pOrTab);
+ if( !untestedTerms ) disableTerm(pLevel, pTerm);
+ }else
+#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
+
+ {
+ /* Case 6: There is no usable index. We must do a complete
+ ** scan of the entire table.
+ */
+ static const u8 aStep[] = { OP_Next, OP_Prev };
+ static const u8 aStart[] = { OP_Rewind, OP_Last };
+ assert( bRev==0 || bRev==1 );
+ if( pTabItem->isRecursive ){
+ /* Tables marked isRecursive have only a single row that is stored in
+ ** a pseudo-cursor. No need to Rewind or Next such cursors. */
+ pLevel->op = OP_Noop;
+ }else{
+ pLevel->op = aStep[bRev];
+ pLevel->p1 = iCur;
+ pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);
+ VdbeCoverageIf(v, bRev==0);
+ VdbeCoverageIf(v, bRev!=0);
+ pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
+ }
+ }
+
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+ pLevel->addrVisit = sqlite3VdbeCurrentAddr(v);
+#endif
+
+ /* Insert code to test every subexpression that can be completely
+ ** computed using the current set of tables.
+ */
+ for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
+ Expr *pE;
+ int skipLikeAddr = 0;
+ testcase( pTerm->wtFlags & TERM_VIRTUAL );
+ testcase( pTerm->wtFlags & TERM_CODED );
+ if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+ if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
+ testcase( pWInfo->untestedTerms==0
+ && (pWInfo->wctrlFlags & WHERE_ONETABLE_ONLY)!=0 );
+ pWInfo->untestedTerms = 1;
+ continue;
+ }
+ pE = pTerm->pExpr;
+ assert( pE!=0 );
+ if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
+ continue;
+ }
+ if( pTerm->wtFlags & TERM_LIKECOND ){
+ assert( pLevel->iLikeRepCntr>0 );
+ skipLikeAddr = sqlite3VdbeAddOp1(v, OP_IfNot, pLevel->iLikeRepCntr);
+ VdbeCoverage(v);
+ }
+ sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
+ if( skipLikeAddr ) sqlite3VdbeJumpHere(v, skipLikeAddr);
+ pTerm->wtFlags |= TERM_CODED;
+ }
+
+ /* Insert code to test for implied constraints based on transitivity
+ ** of the "==" operator.
+ **
+ ** Example: If the WHERE clause contains "t1.a=t2.b" and "t2.b=123"
+ ** and we are coding the t1 loop and the t2 loop has not yet coded,
+ ** then we cannot use the "t1.a=t2.b" constraint, but we can code
+ ** the implied "t1.a=123" constraint.
+ */
+ for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
+ Expr *pE, *pEAlt;
+ WhereTerm *pAlt;
+ if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+ if( (pTerm->eOperator & (WO_EQ|WO_IS))==0 ) continue;
+ if( (pTerm->eOperator & WO_EQUIV)==0 ) continue;
+ if( pTerm->leftCursor!=iCur ) continue;
+ if( pLevel->iLeftJoin ) continue;
+ pE = pTerm->pExpr;
+ assert( !ExprHasProperty(pE, EP_FromJoin) );
+ assert( (pTerm->prereqRight & pLevel->notReady)!=0 );
+ pAlt = sqlite3WhereFindTerm(pWC, iCur, pTerm->u.leftColumn, notReady,
+ WO_EQ|WO_IN|WO_IS, 0);
+ if( pAlt==0 ) continue;
+ if( pAlt->wtFlags & (TERM_CODED) ) continue;
+ testcase( pAlt->eOperator & WO_EQ );
+ testcase( pAlt->eOperator & WO_IS );
+ testcase( pAlt->eOperator & WO_IN );
+ VdbeModuleComment((v, "begin transitive constraint"));
+ pEAlt = sqlite3StackAllocRaw(db, sizeof(*pEAlt));
+ if( pEAlt ){
+ *pEAlt = *pAlt->pExpr;
+ pEAlt->pLeft = pE->pLeft;
+ sqlite3ExprIfFalse(pParse, pEAlt, addrCont, SQLITE_JUMPIFNULL);
+ sqlite3StackFree(db, pEAlt);
+ }
+ }
+
+ /* For a LEFT OUTER JOIN, generate code that will record the fact that
+ ** at least one row of the right table has matched the left table.
+ */
+ if( pLevel->iLeftJoin ){
+ pLevel->addrFirst = sqlite3VdbeCurrentAddr(v);
+ sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
+ VdbeComment((v, "record LEFT JOIN hit"));
+ sqlite3ExprCacheClear(pParse);
+ for(pTerm=pWC->a, j=0; j<pWC->nTerm; j++, pTerm++){
+ testcase( pTerm->wtFlags & TERM_VIRTUAL );
+ testcase( pTerm->wtFlags & TERM_CODED );
+ if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+ if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
+ assert( pWInfo->untestedTerms );
+ continue;
+ }
+ assert( pTerm->pExpr );
+ sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
+ pTerm->wtFlags |= TERM_CODED;
+ }
+ }
+
+ return pLevel->notReady;
+}
update.c
vacuum.c
vtab.c
+ wherecode.c
where.c
parse.c
projects / thirdparty / sqlite.git / commitdiff
