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Allow vector IN(SELECT ...) expressions to use an index if either all the indexed columns are declared NOT NULL or if there is no difference between the expression evaluating to 0 and NULL (as in a WHERE clause).

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FossilOrigin-Name: e2fd6f49b1b145bec09c581cc982b89429643ae9
This commit is contained in:
dan
2016-07-23 20:24:06 +00:00
parent 4097d0ca79
commit ba00e30a3a
6 changed files with 188 additions and 104 deletions
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217
src/expr.c
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@@ -323,6 +323,12 @@ int sqlite3ExprVectorSize(Expr *pExpr){
return pExpr->x.pList->nExpr;
}
/*
** If the expression passed as the first argument is a TK_VECTOR, return
** a pointer to the i'th field of the vector. Or, if the first argument
** points to a sub-select, return a pointer to the i'th returned column
** value. Otherwise, return a copy of the first argument.
*/
static Expr *exprVectorField(Expr *pVector, int i){
if( (pVector->flags & EP_Vector)==0 ){
assert( i==0 );
@@ -1710,6 +1716,13 @@ int sqlite3IsRowid(const char *z){
** a pointer to the SELECT statement. If pX is not a SELECT statement,
** or if the SELECT statement needs to be manifested into a transient
** table, then return NULL.
**
** If parameter bNullSensitive is 0, then this operation will be
** used in a context in which there is no difference between a result
** of 0 and one of NULL. For example:
**
** ... WHERE (?,?) IN (SELECT ...)
**
*/
#ifndef SQLITE_OMIT_SUBQUERY
static Select *isCandidateForInOpt(Expr *pX, int bNullSensitive){
@@ -1870,7 +1883,13 @@ static int sqlite3InRhsIsConstant(Expr *pIn){
** NULL values.
*/
#ifndef SQLITE_OMIT_SUBQUERY
int sqlite3FindInIndex(Parse *pParse, Expr *pX, u32 inFlags, int *prRhsHasNull){
int sqlite3FindInIndex(
Parse *pParse,
Expr *pX,
u32 inFlags,
int *prRhsHasNull,
int *aiMap
){
Select *p; /* SELECT to the right of IN operator */
int eType = 0; /* Type of RHS table. IN_INDEX_* */
int iTab = pParse->nTab++; /* Cursor of the RHS table */
@@ -1887,9 +1906,9 @@ int sqlite3FindInIndex(Parse *pParse, Expr *pX, u32 inFlags, int *prRhsHasNull){
if( pParse->nErr==0 && (p = isCandidateForInOpt(pX, prRhsHasNull!=0))!=0 ){
sqlite3 *db = pParse->db; /* Database connection */
Table *pTab; /* Table <table>. */
i16 iDb; /* Database idx for pTab */
ExprList *pEList = p->pEList;
int nExpr = pEList->nExpr;
i16 iDb; /* Database idx for pTab */
assert( p->pEList!=0 ); /* Because of isCandidateForInOpt(p) */
assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
@@ -1961,6 +1980,7 @@ int sqlite3FindInIndex(Parse *pParse, Expr *pX, u32 inFlags, int *prRhsHasNull){
break;
}
if( j==nExpr ) break;
if( aiMap ) aiMap[i] = j;
}
if( i==nExpr ){
@@ -2023,6 +2043,12 @@ int sqlite3FindInIndex(Parse *pParse, Expr *pX, u32 inFlags, int *prRhsHasNull){
}else{
pX->iTable = iTab;
}
if( aiMap && eType!=IN_INDEX_INDEX_ASC && eType!=IN_INDEX_INDEX_DESC ){
int i, n;
n = sqlite3ExprVectorSize(pX->pLeft);
for(i=0; i<n; i++) aiMap[i] = i;
}
return eType;
}
#endif
@@ -2309,75 +2335,6 @@ int sqlite3CodeSubselect(
}
#endif /* SQLITE_OMIT_SUBQUERY */
#ifndef SQLITE_OMIT_SUBQUERY
void exprCodeVectorIN(
Parse *pParse, /* Parsing and code generating context */
Expr *pExpr, /* The IN expression */
int destIfFalse, /* Jump here if LHS is not contained in the RHS */
int destIfNull /* Jump here if the results are unknown due to NULLs */
){
int i;
int addrNext;
int iSkip;
int r1;
int r2 = sqlite3GetTempReg(pParse);
int r3 = sqlite3GetTempReg(pParse);
int r4 = sqlite3GetTempReg(pParse);
int regResult = sqlite3GetTempReg(pParse);
int nVal = sqlite3ExprVectorSize(pExpr->pLeft);
Expr *pLeft = pExpr->pLeft;
Vdbe *v = pParse->pVdbe;
/* Code the LHS, the <expr> from "<expr> IN (...)". Leave the results in
** an array of nVal registers starting at r1. */
sqlite3ExprCachePush(pParse);
if( pLeft->flags & EP_xIsSelect ){
r1 = sqlite3CodeSubselect(pParse, pLeft, 0, 0);
}else{
r1 = pParse->nMem + 1;
pParse->nMem += nVal;
sqlite3ExprCodeExprList(pParse, pLeft->x.pList, r1, 0, 0);
}
/* Generate an epheremal index containing the contents of the SELECT
** to the right of the "<expr> IN (SELECT ...)" expression. The cursor
** number for the epheremal table is left in pExpr->iTable. */
assert( pExpr->flags & EP_xIsSelect );
sqlite3CodeSubselect(pParse, pExpr, 0, 0);
sqlite3VdbeAddOp2(v, OP_Integer, 0, regResult);
/* Iterate through the ephemeral table just populated */
addrNext = 1 + sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse);
for(i=0; i<nVal; i++){
Expr *p;
CollSeq *pColl;
p = exprVectorField(pLeft, i);
pColl = sqlite3ExprCollSeq(pParse, p);
sqlite3VdbeAddOp3(v, OP_Column, pExpr->iTable, i, r2);
sqlite3VdbeAddOp4(v, OP_Eq, r1+i, i==0?r3:r4, r2, (void*)pColl,P4_COLLSEQ);
sqlite3VdbeChangeP5(v, SQLITE_STOREP2);
VdbeCoverage(v);
if( i!=0 ){
sqlite3VdbeAddOp3(v, OP_And, r3, r4, r4);
}
}
sqlite3VdbeAddOp2(v, OP_If, r4, sqlite3VdbeCurrentAddr(v)+6);
sqlite3VdbeAddOp2(v, OP_IfNot, r4, sqlite3VdbeCurrentAddr(v)+2);
sqlite3VdbeAddOp2(v, OP_Null, 0, regResult);
sqlite3VdbeAddOp2(v, OP_Next, pExpr->iTable, addrNext);
sqlite3VdbeAddOp3(v, OP_If, regResult, destIfNull, 1);
sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
sqlite3ReleaseTempReg(pParse, r2);
sqlite3ReleaseTempReg(pParse, r3);
sqlite3ReleaseTempReg(pParse, r4);
sqlite3ReleaseTempReg(pParse, regResult);
sqlite3ExprCachePop(pParse);
}
#endif
#ifndef SQLITE_OMIT_SUBQUERY
/*
** Generate code for an IN expression.
@@ -2403,36 +2360,64 @@ static void sqlite3ExprCodeIN(
int destIfNull /* Jump here if the results are unknown due to NULLs */
){
int rRhsHasNull = 0; /* Register that is true if RHS contains NULL values */
char affinity; /* Comparison affinity to use */
int eType; /* Type of the RHS */
int r1; /* Temporary use register */
Vdbe *v; /* Statement under construction */
int *aiMap = 0; /* Map from vector field to index column */
char *zAff = 0; /* Affinity string for comparisons */
int nVector; /* Size of vectors for this IN(...) op */
int regSelect = 0;
Expr *pLeft = pExpr->pLeft;
int i;
if( pExpr->pLeft->flags & EP_Vector ){
return exprCodeVectorIN(pParse, pExpr, destIfFalse, destIfNull);
}
nVector = sqlite3ExprVectorSize(pExpr->pLeft);
aiMap = (int*)sqlite3DbMallocZero(
pParse->db, nVector*(sizeof(int) + sizeof(char)) + 1
);
if( !aiMap ) return;
zAff = (char*)&aiMap[nVector];
/* Compute the RHS. After this step, the table with cursor
** pExpr->iTable will contains the values that make up the RHS.
*/
/* Attempt to compute the RHS. After this step, if anything other than
** IN_INDEX_NOOP is returned, the table opened ith cursor pExpr->iTable
** contains the values that make up the RHS. If IN_INDEX_NOOP is returned,
** the RHS has not yet been coded. */
v = pParse->pVdbe;
assert( v!=0 ); /* OOM detected prior to this routine */
VdbeNoopComment((v, "begin IN expr"));
eType = sqlite3FindInIndex(pParse, pExpr,
IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK,
destIfFalse==destIfNull ? 0 : &rRhsHasNull);
destIfFalse==destIfNull ? 0 : &rRhsHasNull, aiMap);
/* Figure out the affinity to use to create a key from the results
** of the expression. affinityStr stores a static string suitable for
** P4 of OP_MakeRecord.
*/
affinity = comparisonAffinity(pExpr);
assert( pParse->nErr || nVector==1 || eType==IN_INDEX_EPH
|| eType==IN_INDEX_INDEX_ASC || eType==IN_INDEX_INDEX_DESC
);
/* Code the LHS, the <expr> from "<expr> IN (...)".
/* Code the LHS, the <expr> from "<expr> IN (...)". If the LHS is a
** vector, then it is stored in an array of nVector registers starting
** at r1.
*/
r1 = sqlite3GetTempRange(pParse, nVector);
sqlite3ExprCachePush(pParse);
r1 = sqlite3GetTempReg(pParse);
sqlite3ExprCode(pParse, pExpr->pLeft, r1);
if( nVector>1 && (pLeft->flags & EP_xIsSelect) ){
regSelect = sqlite3CodeSubselect(pParse, pLeft, 0, 0);
}
for(i=0; i<nVector; i++){
int iCol = aiMap[i];
Expr *pLhs = exprVectorField(pLeft, i);
if( regSelect ){
sqlite3VdbeAddOp3(v, OP_Copy, regSelect+i, r1+iCol, 0);
}else{
sqlite3ExprCode(pParse, pLhs, r1+iCol);
}
zAff[iCol] = sqlite3ExprAffinity(pLhs);
if( pExpr->flags & EP_xIsSelect ){
zAff[iCol] = sqlite3CompareAffinity(
pExpr->x.pSelect->pEList->a[iCol].pExpr, zAff[iCol]
);
}
}
/* If sqlite3FindInIndex() did not find or create an index that is
** suitable for evaluating the IN operator, then evaluate using a
@@ -2460,12 +2445,12 @@ static void sqlite3ExprCodeIN(
(void*)pColl, P4_COLLSEQ);
VdbeCoverageIf(v, ii<pList->nExpr-1);
VdbeCoverageIf(v, ii==pList->nExpr-1);
sqlite3VdbeChangeP5(v, affinity);
sqlite3VdbeChangeP5(v, zAff[0]);
}else{
assert( destIfNull==destIfFalse );
sqlite3VdbeAddOp4(v, OP_Ne, r1, destIfFalse, r2,
(void*)pColl, P4_COLLSEQ); VdbeCoverage(v);
sqlite3VdbeChangeP5(v, affinity | SQLITE_JUMPIFNULL);
sqlite3VdbeChangeP5(v, zAff[0] | SQLITE_JUMPIFNULL);
}
sqlite3ReleaseTempReg(pParse, regToFree);
}
@@ -2480,7 +2465,7 @@ static void sqlite3ExprCodeIN(
/* If the LHS is NULL, then the result is either false or NULL depending
** on whether the RHS is empty or not, respectively.
*/
if( sqlite3ExprCanBeNull(pExpr->pLeft) ){
if( nVector==1 && sqlite3ExprCanBeNull(pExpr->pLeft) ){
if( destIfNull==destIfFalse ){
/* Shortcut for the common case where the false and NULL outcomes are
** the same. */
@@ -2499,10 +2484,50 @@ static void sqlite3ExprCodeIN(
*/
sqlite3VdbeAddOp3(v, OP_SeekRowid, pExpr->iTable, destIfFalse, r1);
VdbeCoverage(v);
}else if( nVector>1 && eType==IN_INDEX_EPH ){
int regNull = sqlite3GetTempReg(pParse);
int r2 = sqlite3GetTempReg(pParse);
int r3 = sqlite3GetTempReg(pParse);
int r4 = sqlite3GetTempReg(pParse);
int addrNext;
int addrIf;
if( destIfFalse!=destIfNull ){
sqlite3VdbeAddOp2(v, OP_Integer, 0, regNull);
}
addrNext = sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse);
for(i=0; i<nVector; i++){
Expr *p;
CollSeq *pColl;
p = exprVectorField(pLeft, i);
pColl = sqlite3ExprCollSeq(pParse, p);
sqlite3VdbeAddOp3(v, OP_Column, pExpr->iTable, i, r2);
sqlite3VdbeAddOp4(v, OP_Eq, r1+i, i?r3:r4, r2, (void*)pColl,P4_COLLSEQ);
sqlite3VdbeChangeP5(v, SQLITE_STOREP2);
if( i!=0 ){
sqlite3VdbeAddOp3(v, OP_And, r3, r4, r4);
}
}
addrIf = sqlite3VdbeAddOp1(v, OP_If, r4);
if( destIfNull!=destIfFalse ){
sqlite3VdbeAddOp2(v, OP_IfNot, r4, sqlite3VdbeCurrentAddr(v)+2);
sqlite3VdbeAddOp2(v, OP_Integer, 1, regNull);
}
sqlite3VdbeAddOp2(v, OP_Next, pExpr->iTable, addrNext+1);
if( destIfNull!=destIfFalse ){
sqlite3VdbeAddOp2(v, OP_If, regNull, destIfNull);
}
sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
sqlite3VdbeChangeP2(v, addrIf, sqlite3VdbeCurrentAddr(v));
sqlite3ReleaseTempReg(pParse, regNull);
sqlite3ReleaseTempReg(pParse, r2);
sqlite3ReleaseTempReg(pParse, r3);
sqlite3ReleaseTempReg(pParse, r4);
}else{
/* In this case, the RHS is an index b-tree.
*/
sqlite3VdbeAddOp4(v, OP_Affinity, r1, 1, 0, &affinity, 1);
sqlite3VdbeAddOp4(v, OP_Affinity, r1, nVector, 0, zAff, nVector);
/* If the set membership test fails, then the result of the
** "x IN (...)" expression must be either 0 or NULL. If the set
@@ -2519,7 +2544,9 @@ static void sqlite3ExprCodeIN(
** Also run this branch if NULL is equivalent to FALSE
** for this particular IN operator.
*/
sqlite3VdbeAddOp4Int(v, OP_NotFound, pExpr->iTable, destIfFalse, r1, 1);
sqlite3VdbeAddOp4Int(
v, OP_NotFound, pExpr->iTable, destIfFalse, r1, nVector
);
VdbeCoverage(v);
}else{
/* In this branch, the RHS of the IN might contain a NULL and
@@ -2545,6 +2572,7 @@ static void sqlite3ExprCodeIN(
}
sqlite3ReleaseTempReg(pParse, r1);
sqlite3ExprCachePop(pParse);
sqlite3DbFree(pParse->db, aiMap);
VdbeComment((v, "end IN expr"));
}
#endif /* SQLITE_OMIT_SUBQUERY */
@@ -4010,7 +4038,7 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
assert( pExpr->op!=TK_GT || op==OP_Le );
assert( pExpr->op!=TK_GE || op==OP_Lt );
switch( pExpr->op | (pExpr->pLeft ? (pExpr->pLeft->flags & EP_Vector) : 0)){
switch( pExpr->op ){
case TK_AND: {
testcase( jumpIfNull==0 );
sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
@@ -4047,6 +4075,8 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
case TK_GE:
case TK_NE:
case TK_EQ: {
if( pExpr->pLeft->flags & EP_Vector ) goto default_expr;
testcase( jumpIfNull==0 );
r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
@@ -4093,6 +4123,7 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
}
#endif
default: {
default_expr:
if( exprAlwaysFalse(pExpr) ){
sqlite3VdbeGoto(v, dest);
}else if( exprAlwaysTrue(pExpr) ){