Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Avoid storing the result register for EXISTS and SELECT in any field of the Expr object - simply return the register number as the return value of the function that codes those expressions. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: | 7253f8fad1efe6b88666f0f8740d247ff07a7640 |
| User & Date: | drh 2009-10-30 13:25:57 |
References
|
2009-10-30
| ||
| 14:05 | • Fixed ticket [6b00e0a3]: The great OP_If bug plus 3 other changes artifact: a67b11ba user: drh | |
Context
|
2009-10-30
| ||
| 14:27 | Increase the version number to 3.6.20. check-in: 61295274 user: drh tags: trunk | |
| 13:25 | Avoid storing the result register for EXISTS and SELECT in any field of the Expr object - simply return the register number as the return value of the function that codes those expressions. check-in: 7253f8fa user: drh tags: trunk | |
|
2009-10-29
| ||
| 13:48 | Reduce the memory required by prepared statements that use the IN operator with a list on the right and an INTEGER PRIMARY KEY on the left. check-in: e7984ad2 user: drh tags: trunk | |
Changes
Changes to src/expr.c.
1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 .... 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 .... 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 .... 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 .... 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 .... 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 |
*/
#ifndef SQLITE_OMIT_SUBQUERY
int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
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 */
int mustBeUnique = (prNotFound==0); /* True if RHS must be unique */
/* Check to see if an existing table or index can be used to
** satisfy the query. This is preferable to generating a new
** ephemeral table.
*/
p = (ExprHasProperty(pX, EP_xIsSelect) ? pX->x.pSelect : 0);
if( ALWAYS(pParse->nErr==0) && isCandidateForInOpt(p) ){
................................................................................
}
}
}
}
}
if( eType==0 ){
/* Could not found an existing able or index to use as the RHS b-tree.
** We will have to generate an ephemeral table to do the job.
*/
int rMayHaveNull = 0;
eType = IN_INDEX_EPH;
if( prNotFound ){
*prNotFound = rMayHaveNull = ++pParse->nMem;
}else if( pX->pLeft->iColumn<0 && !ExprHasAnyProperty(pX, EP_xIsSelect) ){
................................................................................
** all corresponding LHS elements. All this routine does is initialize
** the register given by rMayHaveNull to NULL. Calling routines will take
** care of changing this register value to non-NULL if the RHS is NULL-free.
**
** If rMayHaveNull is zero, that means that the subquery is being used
** for membership testing only. There is no need to initialize any
** registers to indicate the presense or absence of NULLs on the RHS.
*/
#ifndef SQLITE_OMIT_SUBQUERY
void sqlite3CodeSubselect(
Parse *pParse, /* Parsing context */
Expr *pExpr, /* The IN, SELECT, or EXISTS operator */
int rMayHaveNull, /* Register that records whether NULLs exist in RHS */
int isRowid /* If true, LHS of IN operator is a rowid */
){
int testAddr = 0; /* One-time test address */
Vdbe *v = sqlite3GetVdbe(pParse);
if( NEVER(v==0) ) return;
sqlite3ExprCachePush(pParse);
/* This code must be run in its entirety every time it is encountered
** if any of the following is true:
**
** * The right-hand side is a correlated subquery
** * The right-hand side is an expression list containing variables
................................................................................
ExprList *pEList;
assert( !isRowid );
sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
dest.affinity = (u8)affinity;
assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
if( sqlite3Select(pParse, pExpr->x.pSelect, &dest) ){
return;
}
pEList = pExpr->x.pSelect->pEList;
if( ALWAYS(pEList!=0 && pEList->nExpr>0) ){
keyInfo.aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
pEList->a[0].pExpr);
}
}else if( pExpr->x.pList!=0 ){
................................................................................
dest.eDest = SRT_Exists;
sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iParm);
VdbeComment((v, "Init EXISTS result"));
}
sqlite3ExprDelete(pParse->db, pSel->pLimit);
pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &one);
if( sqlite3Select(pParse, pSel, &dest) ){
return;
}
pExpr->iColumn = (i16)dest.iParm;
ExprSetIrreducible(pExpr);
break;
}
}
if( testAddr ){
sqlite3VdbeJumpHere(v, testAddr-1);
}
sqlite3ExprCachePop(pParse, 1);
return;
}
#endif /* SQLITE_OMIT_SUBQUERY */
/*
** Duplicate an 8-byte value
*/
static char *dup8bytes(Vdbe *v, const char *in){
................................................................................
break;
}
#ifndef SQLITE_OMIT_SUBQUERY
case TK_EXISTS:
case TK_SELECT: {
testcase( op==TK_EXISTS );
testcase( op==TK_SELECT );
sqlite3CodeSubselect(pParse, pExpr, 0, 0);
inReg = pExpr->iColumn;
break;
}
case TK_IN: {
int rNotFound = 0;
int rMayHaveNull = 0;
int j2, j3, j4, j5;
char affinity;
|
> > | > > > | > | | | | | | < |
1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 .... 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 .... 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 .... 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 .... 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 .... 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 |
*/
#ifndef SQLITE_OMIT_SUBQUERY
int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
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 */
int mustBeUnique = (prNotFound==0); /* True if RHS must be unique */
assert( pX->op==TK_IN );
/* Check to see if an existing table or index can be used to
** satisfy the query. This is preferable to generating a new
** ephemeral table.
*/
p = (ExprHasProperty(pX, EP_xIsSelect) ? pX->x.pSelect : 0);
if( ALWAYS(pParse->nErr==0) && isCandidateForInOpt(p) ){
................................................................................
}
}
}
}
}
if( eType==0 ){
/* Could not found an existing table or index to use as the RHS b-tree.
** We will have to generate an ephemeral table to do the job.
*/
int rMayHaveNull = 0;
eType = IN_INDEX_EPH;
if( prNotFound ){
*prNotFound = rMayHaveNull = ++pParse->nMem;
}else if( pX->pLeft->iColumn<0 && !ExprHasAnyProperty(pX, EP_xIsSelect) ){
................................................................................
** all corresponding LHS elements. All this routine does is initialize
** the register given by rMayHaveNull to NULL. Calling routines will take
** care of changing this register value to non-NULL if the RHS is NULL-free.
**
** If rMayHaveNull is zero, that means that the subquery is being used
** for membership testing only. There is no need to initialize any
** registers to indicate the presense or absence of NULLs on the RHS.
**
** For a SELECT or EXISTS operator, return the register that holds the
** result. For IN operators or if an error occurs, the return value is 0.
*/
#ifndef SQLITE_OMIT_SUBQUERY
int sqlite3CodeSubselect(
Parse *pParse, /* Parsing context */
Expr *pExpr, /* The IN, SELECT, or EXISTS operator */
int rMayHaveNull, /* Register that records whether NULLs exist in RHS */
int isRowid /* If true, LHS of IN operator is a rowid */
){
int testAddr = 0; /* One-time test address */
int rReg = 0; /* Register storing resulting */
Vdbe *v = sqlite3GetVdbe(pParse);
if( NEVER(v==0) ) return 0;
sqlite3ExprCachePush(pParse);
/* This code must be run in its entirety every time it is encountered
** if any of the following is true:
**
** * The right-hand side is a correlated subquery
** * The right-hand side is an expression list containing variables
................................................................................
ExprList *pEList;
assert( !isRowid );
sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
dest.affinity = (u8)affinity;
assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
if( sqlite3Select(pParse, pExpr->x.pSelect, &dest) ){
return 0;
}
pEList = pExpr->x.pSelect->pEList;
if( ALWAYS(pEList!=0 && pEList->nExpr>0) ){
keyInfo.aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
pEList->a[0].pExpr);
}
}else if( pExpr->x.pList!=0 ){
................................................................................
dest.eDest = SRT_Exists;
sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iParm);
VdbeComment((v, "Init EXISTS result"));
}
sqlite3ExprDelete(pParse->db, pSel->pLimit);
pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &one);
if( sqlite3Select(pParse, pSel, &dest) ){
return 0;
}
rReg = dest.iParm;
ExprSetIrreducible(pExpr);
break;
}
}
if( testAddr ){
sqlite3VdbeJumpHere(v, testAddr-1);
}
sqlite3ExprCachePop(pParse, 1);
return rReg;
}
#endif /* SQLITE_OMIT_SUBQUERY */
/*
** Duplicate an 8-byte value
*/
static char *dup8bytes(Vdbe *v, const char *in){
................................................................................
break;
}
#ifndef SQLITE_OMIT_SUBQUERY
case TK_EXISTS:
case TK_SELECT: {
testcase( op==TK_EXISTS );
testcase( op==TK_SELECT );
inReg = sqlite3CodeSubselect(pParse, pExpr, 0, 0);
break;
}
case TK_IN: {
int rNotFound = 0;
int rMayHaveNull = 0;
int j2, j3, j4, j5;
char affinity;
|
Changes to src/sqliteInt.h.
2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 |
void sqlite3RootPageMoved(Db*, int, int);
void sqlite3Reindex(Parse*, Token*, Token*);
void sqlite3AlterFunctions(sqlite3*);
void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
int sqlite3GetToken(const unsigned char *, int *);
void sqlite3NestedParse(Parse*, const char*, ...);
void sqlite3ExpirePreparedStatements(sqlite3*);
void sqlite3CodeSubselect(Parse *, Expr *, int, int);
void sqlite3SelectPrep(Parse*, Select*, NameContext*);
int sqlite3ResolveExprNames(NameContext*, Expr*);
void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
void sqlite3ColumnDefault(Vdbe *, Table *, int, int);
void sqlite3AlterFinishAddColumn(Parse *, Token *);
void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
|
| |
2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 |
void sqlite3RootPageMoved(Db*, int, int);
void sqlite3Reindex(Parse*, Token*, Token*);
void sqlite3AlterFunctions(sqlite3*);
void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
int sqlite3GetToken(const unsigned char *, int *);
void sqlite3NestedParse(Parse*, const char*, ...);
void sqlite3ExpirePreparedStatements(sqlite3*);
int sqlite3CodeSubselect(Parse *, Expr *, int, int);
void sqlite3SelectPrep(Parse*, Select*, NameContext*);
int sqlite3ResolveExprNames(NameContext*, Expr*);
void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
void sqlite3ColumnDefault(Vdbe *, Table *, int, int);
void sqlite3AlterFinishAddColumn(Parse *, Token *);
void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
|