mirrors/sqlite
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Optimizer now converts OR-connected WHERE-clause terms into an IN operator so

Browse Source 
that they can be used with indices.  There are known problems with the
ORDER BY optimization in this and in several prior check-ins.  This
check-in is not recommended for production use. (CVS 2569)

FossilOrigin-Name: d23c8bf81e508722e92ff1b9c8bc98dc026a31f2
This commit is contained in:
drh 2005-07-29 15:10:17 +00:00
parent ed37800693
commit 6c30be8e51
5 changed files with 146 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
manifest
View File

@ -1,5 +1,5 @@
C The\sBETWEEN\soperator\sin\sa\sWHERE\sclause\sis\snow\sable\sto\suse\sindices.\s(CVS\s2568)
D 2005-07-28T23:12:08
C Optimizer\snow\sconverts\sOR-connected\sWHERE-clause\sterms\sinto\san\sIN\soperator\sso\nthat\sthey\scan\sbe\sused\swith\sindices.\s\sThere\sare\sknown\sproblems\swith\sthe\nORDER\sBY\soptimization\sin\sthis\sand\sin\sseveral\sprior\scheck-ins.\s\sThis\ncheck-in\sis\snot\srecommended\sfor\sproduction\suse.\s(CVS\s2569)
D 2005-07-29T15:10:18
F Makefile.in 22ea9c0fe748f591712d8fe3c6d972c6c173a165
F Makefile.linux-gcc 06be33b2a9ad4f005a5f42b22c4a19dab3cbb5c7
F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@ -38,7 +38,7 @@ F src/callback.c 0910b611e0c158f107ee3ff86f8a371654971e2b
F src/date.c 7444b0900a28da77e57e3337a636873cff0ae940
F src/delete.c be1fc25c9e109cd8cbab42a43ee696263da7c04b
F src/experimental.c 50c1e3b34f752f4ac10c36f287db095c2b61766d
F src/expr.c 0e158f7cc8df562320faa9f2de48cfd856458a52
F src/expr.c c71265b78d383382fa8798ac9436246e3eb6d16c
F src/func.c 2be0799df0c05066a29e589485ebee0b3f756a15
F src/hash.c 2b1b13f7400e179631c83a1be0c664608c8f021f
F src/hash.h 1b0c445e1c89ff2aaad9b4605ba61375af001e84
@ -85,7 +85,7 @@ F src/vdbeapi.c 7f392f0792d1258c958083d7de9eae7c3530c9a6
F src/vdbeaux.c 3732a86566a6be4da4c606e9334baf3fd98667af
F src/vdbefifo.c b8805850afe13b43f1de78d58088cb5d66f88e1e
F src/vdbemem.c da8e8d6f29dd1323f782f000d7cd120027c9ff03
F src/where.c c37799a796f490695211189608e1d5abeb01eea8
F src/where.c c65782be9fff4fd95e4e652f815bbcfd36d5656f
F tclinstaller.tcl 046e3624671962dc50f0481d7c25b38ef803eb42
F test/all.test 7f0988442ab811dfa41793b5b550f5828ce316f3
F test/alter.test 9d6837a3d946b73df692b7cef2a7644d2e2f6bc6
@ -226,7 +226,7 @@ F test/vacuum2.test 5d77e98c458bcdbeecc6327de5107179ba1aa095
F test/varint.test ab7b110089a08b9926ed7390e7e97bdefeb74102
F test/view.test 3c79232a2ee45918c62a0cf90411525899404a76
F test/where.test b6ab0f64adc5fbb4259f284b19da6cd9aeadc711
F test/where2.test 8696c35cd31b0a298de046f3fb6b684486a8b472
F test/where2.test 6e8c3369e315a609b207734f57a49e21ed838c04
F tool/diffdb.c 7524b1b5df217c20cd0431f6789851a4e0cb191b
F tool/lemon.c c88936c67f6411608db8fa4254d254f509fa40f6
F tool/lempar.c f0c30abcae762a7d1eb37cd88b2232ab8dd625fb
@ -289,7 +289,7 @@ F www/tclsqlite.tcl 425be741b8ae664f55cb1ef2371aab0a75109cf9
F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
F www/version3.tcl a99cf5f6d8bd4d5537584a2b342f0fb9fa601d8b
F www/whentouse.tcl 528299b8316726dbcc5548e9aa0648c8b1bd055b
P 4b02703dec71aa78e5f8d8cab5b950966a4c6abc
R 5cec6ff48a1212708f6b9493ee851780
P cdf8c9584b945212e065e044df801c207aedb675
R 5611aa11dab02620cd1e954cb8436ec6
U drh
Z 6e3389c38b1260ced7a3d44c47196b06
Z 0d093f02ef16efa0e6b90a80fd1aefbf

2
manifest.uuid
View File

@ -1 +1 @@
cdf8c9584b945212e065e044df801c207aedb675
d23c8bf81e508722e92ff1b9c8bc98dc026a31f2

4
src/expr.c
View File

@ -12,7 +12,7 @@
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.213 2005/07/21 18:23:20 drh Exp $
** $Id: expr.c,v 1.214 2005/07/29 15:10:18 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@ -1334,7 +1334,7 @@ void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
** this code only executes once. Because for a non-constant
** expression we need to rerun this code each time.
*/
if( testAddr>=0 && !sqlite3ExprIsConstant(pE2) ){
if( testAddr>0 && !sqlite3ExprIsConstant(pE2) ){
VdbeOp *aOp = sqlite3VdbeGetOp(v, testAddr-1);
int i;
for(i=0; i<4; i++){

110
src/where.c
View File

@ -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 1.156 2005/07/28 23:12:08 drh Exp $
** $Id: where.c,v 1.157 2005/07/29 15:10:18 drh Exp $
*/
#include "sqliteInt.h"
@ -82,10 +82,10 @@ struct WhereTerm {
Expr *pExpr; /* Pointer to the subexpression */
u16 idx; /* Index of this term in pWC->a[] */
i16 iPartner; /* Disable pWC->a[iPartner] when this term disabled */
u16 flags; /* Bit flags. See below */
i16 leftCursor; /* Cursor number of X in "X <op> <expr>" */
i16 leftColumn; /* Column number of X in "X <op> <expr>" */
u16 operator; /* A WO_xx value describing <op> */
u8 flags; /* Bit flags. See below */
u8 nPartner; /* Number of partners that must disable us */
WhereClause *pWC; /* The clause this term is part of */
Bitmask prereqRight; /* Bitmask of tables used by pRight */
@ -95,9 +95,11 @@ struct WhereTerm {
/*
** Allowed values of WhereTerm.flags
*/
#define TERM_DYNAMIC 0x0001 /* Need to call sqlite3ExprDelete(pExpr) */
#define TERM_VIRTUAL 0x0002 /* Added by the optimizer. Do not code */
#define TERM_CODED 0x0004 /* This term is already coded */
#define TERM_DYNAMIC 0x01 /* Need to call sqlite3ExprDelete(pExpr) */
#define TERM_VIRTUAL 0x02 /* Added by the optimizer. Do not code */
#define TERM_CODED 0x04 /* This term is already coded */
#define TERM_PARTNERED 0x08 /* Has a virtual partner */
#define TERM_OR_OK 0x10 /* Used during OR-clause processing */
/*
** An instance of the following structure holds all information about a
@ -225,8 +227,9 @@ static WhereTerm *whereClauseInsert(WhereClause *pWC, Expr *p, int flags){
/*
** This routine identifies subexpressions in the WHERE clause where
** each subexpression is separate by the AND operator. aSlot is
** filled with pointers to the subexpressions. For example:
** each subexpression is separate by the AND operator or some other
** operator specified in the op parameter. The WhereClause structure
** is filled with pointers to subexpressions. For example:
**
** WHERE a=='hello' AND coalesce(b,11)<10 AND (c+12!=d OR c==22)
** \________/ \_______________/ \________________/
@ -239,13 +242,13 @@ static WhereTerm *whereClauseInsert(WhereClause *pWC, Expr *p, int flags){
** the WhereClause.a[] array. This array grows as needed to contain
** all terms of the WHERE clause.
*/
static void whereSplit(WhereClause *pWC, Expr *pExpr){
static void whereSplit(WhereClause *pWC, Expr *pExpr, int op){
if( pExpr==0 ) return;
if( pExpr->op!=TK_AND ){
if( pExpr->op!=op ){
whereClauseInsert(pWC, pExpr, 0);
}else{
whereSplit(pWC, pExpr->pLeft);
whereSplit(pWC, pExpr->pRight);
whereSplit(pWC, pExpr->pLeft, op);
whereSplit(pWC, pExpr->pRight, op);
}
}
@ -433,6 +436,26 @@ static WhereTerm *findTerm(
return 0;
}
/* Forward reference */
static void exprAnalyze(SrcList*, ExprMaskSet*, WhereTerm*);
/*
** Call exprAnalyze on all terms in a WHERE clause.
**
**
*/
static void exprAnalyzeAll(
SrcList *pTabList, /* the FROM clause */
ExprMaskSet *pMaskSet, /* table masks */
WhereClause *pWC /* the WHERE clause to be analyzed */
){
WhereTerm *pTerm;
int i;
for(i=pWC->nTerm-1, pTerm=pWC->a; i>=0; i--, pTerm++){
exprAnalyze(pTabList, pMaskSet, pTerm);
}
}
/*
** The input to this routine is an WhereTerm structure with only the
** "pExpr" field filled in. The job of this routine is to analyze the
@ -479,6 +502,7 @@ static void exprAnalyze(
if( pNew==0 ) return;
pNew->iPartner = pTerm->idx;
pTerm->nPartner = 1;
pTerm->flags |= TERM_PARTNERED;
}else{
pDup = pExpr;
pNew = pTerm;
@ -515,7 +539,63 @@ static void exprAnalyze(
pTerm->nPartner = 2;
}
/* Attempt to convert OR-connected terms into an IN operator so that
** they can make use of indices.
*/
else if( pExpr->op==TK_OR ){
int ok;
int i, j;
int iColumn, iCursor;
WhereClause sOr;
WhereTerm *pOrTerm;
assert( (pTerm->flags & TERM_DYNAMIC)==0 );
whereClauseInit(&sOr, pTerm->pWC->pParse);
whereSplit(&sOr, pExpr, TK_OR);
exprAnalyzeAll(pSrc, pMaskSet, &sOr);
assert( sOr.nTerm>0 );
j = 0;
do{
iColumn = sOr.a[j].leftColumn;
iCursor = sOr.a[j].leftCursor;
ok = iCursor>=0;
for(i=sOr.nTerm-1, pOrTerm=sOr.a; i>=0 && ok; i--, pOrTerm++){
if( pOrTerm->operator!=WO_EQ ){
goto or_not_possible;
}
if( pOrTerm->leftCursor==iCursor && pOrTerm->leftColumn==iColumn ){
pOrTerm->flags |= TERM_OR_OK;
}else if( (pOrTerm->flags & TERM_PARTNERED)!=0 ||
((pOrTerm->flags & TERM_VIRTUAL)!=0 &&
(sOr.a[pOrTerm->iPartner].flags & TERM_OR_OK)!=0) ){
pOrTerm->flags &= ~TERM_OR_OK;
}else{
ok = 0;
}
}
}while( !ok && (sOr.a[j++].flags & TERM_PARTNERED)!=0 && j<sOr.nTerm );
if( ok ){
ExprList *pList = 0;
Expr *pNew, *pDup;
for(i=sOr.nTerm-1, pOrTerm=sOr.a; i>=0 && ok; i--, pOrTerm++){
if( (pOrTerm->flags & TERM_OR_OK)==0 ) continue;
pDup = sqlite3ExprDup(pOrTerm->pExpr->pRight);
pList = sqlite3ExprListAppend(pList, pDup, 0);
}
pDup = sqlite3Expr(TK_COLUMN, 0, 0, 0);
if( pDup ){
pDup->iTable = iCursor;
pDup->iColumn = iColumn;
}
pNew = sqlite3Expr(TK_IN, pDup, 0, 0);
if( pNew ) pNew->pList = pList;
pTerm->pExpr = pNew;
pTerm->flags |= TERM_DYNAMIC;
exprAnalyze(pSrc, pMaskSet, pTerm);
}
or_not_possible:
whereClauseClear(&sOr);
}
}
@ -1196,7 +1276,7 @@ WhereInfo *sqlite3WhereBegin(
*/
initMaskSet(&maskSet);
whereClauseInit(&wc, pParse);
whereSplit(&wc, pWhere);
whereSplit(&wc, pWhere, TK_AND);
/* Allocate and initialize the WhereInfo structure that will become the
** return value.
@ -1225,9 +1305,7 @@ WhereInfo *sqlite3WhereBegin(
for(i=0; i<pTabList->nSrc; i++){
createMask(&maskSet, pTabList->a[i].iCursor);
}
for(i=wc.nTerm-1; i>=0; i--){
exprAnalyze(pTabList, &maskSet, &wc.a[i]);
}
exprAnalyzeAll(pTabList, &maskSet, &wc);
/* Chose the best index to use for each table in the FROM clause.
**

43
test/where2.test
View File

@ -12,7 +12,7 @@
# focus of this file is testing the use of indices in WHERE clauses
# based on recent changes to the optimizer.
#
# $Id: where2.test,v 1.2 2005/07/28 23:12:08 drh Exp $
# $Id: where2.test,v 1.3 2005/07/29 15:10:19 drh Exp $
set testdir [file dirname $argv0]
source $testdir/tester.tcl
@ -201,6 +201,45 @@ do_test where2-5.2 {
}
} {99 6 10000 10006 sort t1 i1w}
integrity_check {where2-99.0}
# Verify that OR clauses get translated into IN operators.
#
do_test where2-6.1 {
queryplan {
SELECT * FROM t1 WHERE w=99 OR w=100 ORDER BY +w
}
} {99 6 10000 10006 100 6 10201 10207 sort t1 i1w}
do_test where2-6.2 {
queryplan {
SELECT * FROM t1 WHERE w=99 OR w=100 OR 6=w ORDER BY +w
}
} {6 2 49 51 99 6 10000 10006 100 6 10201 10207 sort t1 i1w}
do_test where2-6.3 {
queryplan {
SELECT * FROM t1 WHERE w=99 OR w=100 OR 6=+w ORDER BY +w
}
} {6 2 49 51 99 6 10000 10006 100 6 10201 10207 sort t1 {}}
do_test where2-6.4 {
queryplan {
SELECT * FROM t1 WHERE w=99 OR +w=100 OR 6=w ORDER BY +w
}
} {6 2 49 51 99 6 10000 10006 100 6 10201 10207 sort t1 {}}
if 0 { ##### FIX ME #####
do_test where2-6.5 {
queryplan {
SELECT b.* FROM t1 a, t1 b
WHERE a.w=1 AND (a.y=b.z OR b.z=10)
ORDER BY +b.w
}
} {1 0 4 4 2 1 9 10 sort a i1w b i1zyx}
do_test where2-6.6 {
queryplan {
SELECT b.* FROM t1 a, t1 b
WHERE a.w=1 AND (b.z=10 OR a.y=b.z OR b.z=10)
ORDER BY +b.w
}
} {1 0 4 4 2 1 9 10 sort a i1w b i1zyx}
}
finish_test