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The query optimizer does a better job of optimizing out ORDER BY clauses

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that contain the rowid or which use indices that contain the rowid.
Ticket #2116. (CVS 3536)

FossilOrigin-Name: f245f5c2c2d337fe6458824beb7f9e721837765f
This commit is contained in:
drh 2006-12-20 03:24:19 +00:00
parent 2b7acc3551
commit cc19254de9
4 changed files with 197 additions and 29 deletions
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14
manifest
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@ -1,5 +1,5 @@
C Allow\sconstraint\snames\son\sDEFAULT\svalues\sin\sa\stable\sdefinition.\nTicket\s#2109.\s(CVS\s3535)
D 2006-12-20T02:15:00
C The\squery\soptimizer\sdoes\sa\sbetter\sjob\sof\soptimizing\sout\sORDER\sBY\sclauses\nthat\scontain\sthe\srowid\sor\swhich\suse\sindices\sthat\scontain\sthe\srowid.\nTicket\s#2116.\s(CVS\s3536)
D 2006-12-20T03:24:19
F Makefile.in 8e14898d41a53033ecb687d93c9cd5d109fb9ae3
F Makefile.linux-gcc 2d8574d1ba75f129aba2019f0b959db380a90935
F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@ -129,7 +129,7 @@ F src/vdbeaux.c 05cc6f0f82b86dfb4c356e06ab07ec8cc83a2eda
F src/vdbefifo.c 9efb94c8c3f4c979ebd0028219483f88e57584f5
F src/vdbemem.c 26623176bf1c616aa478da958fac49502491a921
F src/vtab.c aa30e940058ea56a1b7a9a7019ec21d307316fb4
F src/where.c b34cc2c7f753cdf76aa37a71e579c2e266e50958
F src/where.c f55d4459a122457a135cf9ec859bf28777d9156f
F tclinstaller.tcl 046e3624671962dc50f0481d7c25b38ef803eb42
F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
F test/all.test b62fcd122052efaff1b0979aefa2dd65cfc8ee52
@ -348,7 +348,7 @@ F test/vtab6.test ec0036f29f8a803da9935206f2d9d1b6a8026392
F test/vtab7.test 5f9ef9fb84733e928d5d0267c821072561b198d5
F test/vtab9.test 87afba55339b0c255e9697fbfb5bfb6120505d9d
F test/vtab_err.test c07f7665dd90bc757f80f05e7951d826eda9bc48
F test/where.test ee7c9a6659b07e1ee61177f6e7ff71565ee2c9df
F test/where.test 8dcc1b1a6f17b6bad2dc6a9917eafe62d4ea57eb
F test/where2.test 61d5b20d9bedc8788a773bbdc5b2ef887725928e
F test/where3.test 0a30fe9808b0fa01c46d0fcf4fac0bf6cf75bb30
F tool/diffdb.c 7524b1b5df217c20cd0431f6789851a4e0cb191b
@ -423,7 +423,7 @@ F www/tclsqlite.tcl bb0d1357328a42b1993d78573e587c6dcbc964b9
F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
F www/whentouse.tcl 97e2b5cd296f7d8057e11f44427dea8a4c2db513
P c3d118b40811b201e4a98b62549c5439d7d5098d
R ee31e902c9098dae721605bcf38ca561
P 893d58c23da2a9b900a13eaa5202d94429862136
R b71e90ccc82c8a1640aa72f2c870612e
U drh
Z 6de8d7d606a906d10c3edc457d084a8d
Z 9fec3d60f3cf9eea1be494a067e0f511

2
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@ -1 +1 @@
893d58c23da2a9b900a13eaa5202d94429862136
f245f5c2c2d337fe6458824beb7f9e721837765f

58
src/where.c
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@ -16,7 +16,7 @@
** so is applicable. Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.233 2006/12/16 16:25:16 drh Exp $
** $Id: where.c,v 1.234 2006/12/20 03:24:19 drh Exp $
*/
#include "sqliteInt.h"
@ -868,11 +868,19 @@ static int isSortingIndex(
/* Match terms of the ORDER BY clause against columns of
** the index.
**
** Note that indices have pIdx->nColumn regular columns plus
** one additional column containing the rowid. The rowid column
** of the index is also allowed to match against the ORDER BY
** clause.
*/
for(i=j=0, pTerm=pOrderBy->a; j<nTerm && i<pIdx->nColumn; i++){
for(i=j=0, pTerm=pOrderBy->a; j<nTerm && i<=pIdx->nColumn; i++){
Expr *pExpr; /* The expression of the ORDER BY pTerm */
CollSeq *pColl; /* The collating sequence of pExpr */
int termSortOrder; /* Sort order for this term */
int iColumn; /* The i-th column of the index. -1 for rowid */
int iSortOrder; /* 1 for DESC, 0 for ASC on the i-th index term */
const char *zColl; /* Name of the collating sequence for i-th index term */
pExpr = pTerm->pExpr;
if( pExpr->op!=TK_COLUMN || pExpr->iTable!=base ){
@ -881,9 +889,22 @@ static int isSortingIndex(
return 0;
}
pColl = sqlite3ExprCollSeq(pParse, pExpr);
if( !pColl ) pColl = db->pDfltColl;
if( pExpr->iColumn!=pIdx->aiColumn[i] ||
sqlite3StrICmp(pColl->zName, pIdx->azColl[i]) ){
if( !pColl ){
pColl = db->pDfltColl;
}
if( i<pIdx->nColumn ){
iColumn = pIdx->aiColumn[i];
if( iColumn==pIdx->pTable->iPKey ){
iColumn = -1;
}
iSortOrder = pIdx->aSortOrder[i];
zColl = pIdx->azColl[i];
}else{
iColumn = -1;
iSortOrder = 0;
zColl = pColl->zName;
}
if( pExpr->iColumn!=iColumn || sqlite3StrICmp(pColl->zName, zColl) ){
/* Term j of the ORDER BY clause does not match column i of the index */
if( i<nEqCol ){
/* If an index column that is constrained by == fails to match an
@ -899,8 +920,8 @@ static int isSortingIndex(
}
assert( pIdx->aSortOrder!=0 );
assert( pTerm->sortOrder==0 || pTerm->sortOrder==1 );
assert( pIdx->aSortOrder[i]==0 || pIdx->aSortOrder[i]==1 );
termSortOrder = pIdx->aSortOrder[i] ^ pTerm->sortOrder;
assert( iSortOrder==0 || iSortOrder==1 );
termSortOrder = iSortOrder ^ pTerm->sortOrder;
if( i>nEqCol ){
if( termSortOrder!=sortOrder ){
/* Indices can only be used if all ORDER BY terms past the
@ -912,13 +933,25 @@ static int isSortingIndex(
}
j++;
pTerm++;
if( iColumn<0 ){
/* If the indexed column is the primary key and everything matches
** so far, then we are assured that the index can be used to sort
** because the primary key is unique and so none of the other columns
** will make any difference
*/
j = nTerm;
}
}
/* The index can be used for sorting if all terms of the ORDER BY clause
** are covered.
*/
*pbRev = sortOrder!=0;
if( j>=nTerm ){
*pbRev = sortOrder!=0;
/* All terms of the ORDER BY clause are covered by this index so
** this index can be used for sorting. */
return 1;
}
if( j==pIdx->nColumn && pIdx->onError!=OE_None ){
/* All terms of this index match some prefix of the ORDER BY clause
** and this index is UNIQUE, so this index can be used for sorting. */
return 1;
}
return 0;
@ -939,8 +972,7 @@ static int sortableByRowid(
assert( pOrderBy!=0 );
assert( pOrderBy->nExpr>0 );
p = pOrderBy->a[0].pExpr;
if( pOrderBy->nExpr==1 && p->op==TK_COLUMN && p->iTable==base
&& p->iColumn==-1 ){
if( p->op==TK_COLUMN && p->iTable==base && p->iColumn==-1 ){
*pbRev = pOrderBy->a[0].sortOrder;
return 1;
}

152
test/where.test
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@ -11,7 +11,7 @@
# This file implements regression tests for SQLite library. The
# focus of this file is testing the use of indices in WHERE clases.
#
# $Id: where.test,v 1.38 2005/11/14 22:29:06 drh Exp $
# $Id: where.test,v 1.39 2006/12/20 03:24:19 drh Exp $
set testdir [file dirname $argv0]
source $testdir/tester.tcl
@ -589,22 +589,22 @@ do_test where-6.21 {
cksort {
SELECT y FROM t1 ORDER BY rowid, y LIMIT 3;
}
} {4 9 16 sort}
} {4 9 16 nosort}
do_test where-6.22 {
cksort {
SELECT y FROM t1 ORDER BY rowid, y DESC LIMIT 3;
}
} {4 9 16 sort}
} {4 9 16 nosort}
do_test where-6.23 {
cksort {
SELECT y FROM t1 WHERE y>4 ORDER BY rowid, w, x LIMIT 3;
}
} {9 16 25 sort}
} {9 16 25 nosort}
do_test where-6.24 {
cksort {
SELECT y FROM t1 WHERE y>=9 ORDER BY rowid, x DESC, w LIMIT 3;
}
} {9 16 25 sort}
} {9 16 25 nosort}
do_test where-6.25 {
cksort {
SELECT y FROM t1 WHERE y>4 AND y<25 ORDER BY rowid;
@ -619,7 +619,7 @@ do_test where-6.27 {
cksort {
SELECT y FROM t1 WHERE y<=25 ORDER BY _rowid_, w+y;
}
} {4 9 16 25 sort}
} {4 9 16 25 nosort}
# Tests for reverse-order sorting.
@ -793,7 +793,7 @@ do_test where-7.34 {
cksort {
SELECT y FROM t1 WHERE y<25 AND y>4 ORDER BY rowid DESC, y DESC
}
} {16 9 sort}
} {16 9 nosort}
do_test where-7.35 {
cksort {
SELECT y FROM t1 WHERE y<25 AND y>=4 ORDER BY rowid DESC
@ -874,7 +874,6 @@ do_test where-10.4 {
# that array.
#
do_test where-11.1 {
btree_breakpoint
execsql {
CREATE TABLE t99(Dte INT, X INT);
DELETE FROM t99 WHERE (Dte = 2451337) OR (Dte = 2451339) OR
@ -902,6 +901,143 @@ btree_breakpoint
}
} {}
# Ticket #2116: Make sure sorting by index works well with nn INTEGER PRIMARY
# KEY.
#
do_test where-12.1 {
execsql {
CREATE TABLE t6(a INTEGER PRIMARY KEY, b TEXT);
INSERT INTO t6 VALUES(1,'one');
INSERT INTO t6 VALUES(4,'four');
CREATE INDEX t6i1 ON t6(b);
}
cksort {
SELECT * FROM t6 ORDER BY b;
}
} {4 four 1 one nosort}
do_test where-12.2 {
cksort {
SELECT * FROM t6 ORDER BY b, a;
}
} {4 four 1 one nosort}
do_test where-12.3 {
cksort {
SELECT * FROM t6 ORDER BY a;
}
} {1 one 4 four nosort}
do_test where-12.4 {
cksort {
SELECT * FROM t6 ORDER BY a, b;
}
} {1 one 4 four nosort}
do_test where-12.5 {
cksort {
SELECT * FROM t6 ORDER BY b DESC;
}
} {1 one 4 four nosort}
do_test where-12.6 {
cksort {
SELECT * FROM t6 ORDER BY b DESC, a DESC;
}
} {1 one 4 four nosort}
do_test where-12.7 {
cksort {
SELECT * FROM t6 ORDER BY b DESC, a ASC;
}
} {1 one 4 four sort}
do_test where-12.8 {
cksort {
SELECT * FROM t6 ORDER BY b ASC, a DESC;
}
} {4 four 1 one sort}
do_test where-12.9 {
cksort {
SELECT * FROM t6 ORDER BY a DESC;
}
} {4 four 1 one nosort}
do_test where-12.10 {
cksort {
SELECT * FROM t6 ORDER BY a DESC, b DESC;
}
} {4 four 1 one nosort}
do_test where-12.11 {
cksort {
SELECT * FROM t6 ORDER BY a DESC, b ASC;
}
} {4 four 1 one nosort}
do_test where-12.12 {
cksort {
SELECT * FROM t6 ORDER BY a ASC, b DESC;
}
} {1 one 4 four nosort}
do_test where-13.1 {
execsql {
CREATE TABLE t7(a INTEGER PRIMARY KEY, b TEXT);
INSERT INTO t7 VALUES(1,'one');
INSERT INTO t7 VALUES(4,'four');
CREATE INDEX t7i1 ON t7(b);
}
cksort {
SELECT * FROM t7 ORDER BY b;
}
} {4 four 1 one nosort}
do_test where-13.2 {
cksort {
SELECT * FROM t7 ORDER BY b, a;
}
} {4 four 1 one nosort}
do_test where-13.3 {
cksort {
SELECT * FROM t7 ORDER BY a;
}
} {1 one 4 four nosort}
do_test where-13.4 {
cksort {
SELECT * FROM t7 ORDER BY a, b;
}
} {1 one 4 four nosort}
do_test where-13.5 {
cksort {
SELECT * FROM t7 ORDER BY b DESC;
}
} {1 one 4 four nosort}
do_test where-13.6 {
cksort {
SELECT * FROM t7 ORDER BY b DESC, a DESC;
}
} {1 one 4 four nosort}
do_test where-13.7 {
cksort {
SELECT * FROM t7 ORDER BY b DESC, a ASC;
}
} {1 one 4 four sort}
do_test where-13.8 {
cksort {
SELECT * FROM t7 ORDER BY b ASC, a DESC;
}
} {4 four 1 one sort}
do_test where-13.9 {
cksort {
SELECT * FROM t7 ORDER BY a DESC;
}
} {4 four 1 one nosort}
do_test where-13.10 {
cksort {
SELECT * FROM t7 ORDER BY a DESC, b DESC;
}
} {4 four 1 one nosort}
do_test where-13.11 {
cksort {
SELECT * FROM t7 ORDER BY a DESC, b ASC;
}
} {4 four 1 one nosort}
do_test where-13.12 {
cksort {
SELECT * FROM t7 ORDER BY a ASC, b DESC;
}
} {1 one 4 four nosort}
integrity_check {where-99.0}