mirrors
/
sqlite
mirror of https://github.com/sqlite/sqlite
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Make sure that the optimizer realizes that an "x IS NULL" contraint does not 

necessarily give a single-row result even on a UNIQUE index.  Ticket #3824. (CVS 6545)

FossilOrigin-Name: 207335fdbf992a2f5bc5982b3163a38016ba1b21
This commit is contained in:
drh 2009-04-24 14:51:42 +00:00
parent 4598b8e4a1
commit 46619d6787
4 changed files with 117 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
manifest
View File

@ -1,5 +1,5 @@
C Make\sselecting\sthe\sasynchronous\sIO\sfile-locking\smode\sa\sruntime\soperation.\sStill\suntested.\s(CVS\s6544)
D 2009-04-24T10:13:06
C Make\ssure\sthat\sthe\soptimizer\srealizes\sthat\san\s"x\sIS\sNULL"\scontraint\sdoes\snot\nnecessarily\sgive\sa\ssingle-row\sresult\seven\son\sa\sUNIQUE\sindex.\s\sTicket\s#3824.\s(CVS\s6545)
D 2009-04-24T14:51:42
F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
F Makefile.in 583e87706abc3026960ed759aff6371faf84c211
F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@ -212,7 +212,7 @@ F src/vdbeblob.c e67757450ae8581a8b354d9d7e467e41502dfe38
F src/vdbemem.c 111d8193859d16aefd5d3cb57472808584ea5503
F src/vtab.c 6118d71c5137e20a7ac51fb5d9beb0361fbedb89
F src/walker.c 7cdf63223c953d4343c6833e940f110281a378ee
F src/where.c 6f7199cff0f05934bdadd6c67a0c14c0cbf5bcb4
F src/where.c 5eaf44228221e541911fb530d6dceb1e0e37157f
F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
F test/alias.test 4529fbc152f190268a15f9384a5651bbbabc9d87
F test/all.test 14165b3e32715b700b5f0cbf8f6e3833dda0be45
@ -643,6 +643,7 @@ F test/tkt3762.test 2a9f3b03df44ec49ec0cfa8d5da6574c2a7853df
F test/tkt3773.test 430b06567ce40285dfd2c4834a2a61816403efeb
F test/tkt3791.test a6624b9a80b216a26cf473607f42f3e51898c267
F test/tkt3793.test 3aa2efe55bc31fc9459618feea2016ea9a52b2af
F test/tkt3824.test df7c288c9b50c0ef531e56907bb2eed4aa1a4705
F test/tokenize.test ce430a7aed48fc98301611429595883fdfcab5d7
F test/trace.test 19ffbc09885c3321d56358a5738feae8587fb377
F test/trans.test 8b79967a7e085289ec64890c6fdf9d089e1b4a5f
@ -723,7 +724,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
P 92bc6be2a86f8a68ceded2bc08fe7d6ff23b56fb
R d1fe56ed7757cac24f050d623f1a6f33
U danielk1977
Z 741711df9244c68ea2afca1186c054bc
P 577277e84a05707b8c21aa08bc5fc314c1ac38ac
R 0206ac4aa85a991e57e63aae8cfedcce
U drh
Z c576963fd7ebe23db6a9694028a5b0e6

2
manifest.uuid
View File

@ -1 +1 @@
577277e84a05707b8c21aa08bc5fc314c1ac38ac
207335fdbf992a2f5bc5982b3163a38016ba1b21

32
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 1.388 2009/04/23 13:22:44 drh Exp $
** $Id: where.c,v 1.389 2009/04/24 14:51:42 drh Exp $
*/
#include "sqliteInt.h"
@ -226,11 +226,12 @@ struct WhereCost {
*/
#define WHERE_ROWID_EQ 0x00001000 /* rowid=EXPR or rowid IN (...) */
#define WHERE_ROWID_RANGE 0x00002000 /* rowid<EXPR and/or rowid>EXPR */
#define WHERE_COLUMN_EQ 0x00010000 /* x=EXPR or x IN (...) */
#define WHERE_COLUMN_EQ 0x00010000 /* x=EXPR or x IN (...) or x IS NULL */
#define WHERE_COLUMN_RANGE 0x00020000 /* x<EXPR and/or x>EXPR */
#define WHERE_COLUMN_IN 0x00040000 /* x IN (...) */
#define WHERE_INDEXED 0x00070000 /* Anything that uses an index */
#define WHERE_IN_ABLE 0x00071000 /* Able to support an IN operator */
#define WHERE_COLUMN_NULL 0x00080000 /* x IS NULL */
#define WHERE_INDEXED 0x000f0000 /* Anything that uses an index */
#define WHERE_IN_ABLE 0x000f1000 /* Able to support an IN operator */
#define WHERE_TOP_LIMIT 0x00100000 /* x<EXPR or x<=EXPR constraint */
#define WHERE_BTM_LIMIT 0x00200000 /* x>EXPR or x>=EXPR constraint */
#define WHERE_IDX_ONLY 0x00800000 /* Use index only - omit table */
@ -2030,9 +2031,10 @@ static void bestBtreeIndex(
WHERETRACE(("... index %s:\n", pProbe->zName));
/* Count the number of columns in the index that are satisfied
** by x=EXPR constraints or x IN (...) constraints. For a term
** of the form x=EXPR we only have to do a single binary search.
** But for x IN (...) we have to do a number of binary searched
** by x=EXPR or x IS NULL constraints or x IN (...) constraints.
** For a term of the form x=EXPR or x IS NULL we only have to do
** a single binary search. But for x IN (...) we have to do a
** number of binary searched
** equal to the number of entries on the RHS of the IN operator.
** The inMultipler variable with try to estimate the number of
** binary searches needed.
@ -2052,6 +2054,8 @@ static void bestBtreeIndex(
}else if( pExpr->x.pList ){
inMultiplier *= pExpr->x.pList->nExpr + 1;
}
}else if( pTerm->eOperator & WO_ISNULL ){
wsFlags |= WHERE_COLUMN_NULL;
}
}
nRow = pProbe->aiRowEst[i] * inMultiplier;
@ -2064,9 +2068,12 @@ static void bestBtreeIndex(
}
cost = nRow + inMultiplier*estLog(pProbe->aiRowEst[0]);
nEq = i;
if( pProbe->onError!=OE_None && (wsFlags & WHERE_COLUMN_IN)==0
&& nEq==pProbe->nColumn ){
wsFlags |= WHERE_UNIQUE;
if( pProbe->onError!=OE_None && nEq==pProbe->nColumn ){
testcase( wsFlags & WHERE_COLUMN_IN );
testcase( wsFlags & WHERE_COLUMN_NULL );
if( (wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_NULL))==0 ){
wsFlags |= WHERE_UNIQUE;
}
}
WHERETRACE(("...... nEq=%d inMult=%.9g nRow=%.9g cost=%.9g\n",
nEq, inMultiplier, nRow, cost));
@ -2097,8 +2104,9 @@ static void bestBtreeIndex(
/* Add the additional cost of sorting if that is a factor.
*/
if( pOrderBy ){
if( (wsFlags & WHERE_COLUMN_IN)==0 &&
isSortingIndex(pParse,pWC->pMaskSet,pProbe,iCur,pOrderBy,nEq,&rev) ){
if( (wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_NULL))==0
&& isSortingIndex(pParse,pWC->pMaskSet,pProbe,iCur,pOrderBy,nEq,&rev)
){
if( wsFlags==0 ){
wsFlags = WHERE_COLUMN_RANGE;
}

88
test/tkt3824.test Normal file
View File

@ -0,0 +1,88 @@
# 2009 April 24
#
# 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.
#
#***********************************************************************
#
# Ticket #3824
#
# When you use an "IS NULL" constraint on a UNIQUE index, the result
# is not necessarily UNIQUE. Make sure the optimizer does not assume
# uniqueness.
#
# $Id: tkt3824.test,v 1.1 2009/04/24 14:51:42 drh Exp $
set testdir [file dirname $argv0]
source $testdir/tester.tcl
proc execsql_status {sql {db db}} {
set result [uplevel $db eval [list $sql]]
if {[db status sort]} {
concat $result sort
} else {
concat $result nosort
}
}
do_test tkt3824-1.1 {
db eval {
CREATE TABLE t1(a,b);
INSERT INTO t1 VALUES(1,NULL);
INSERT INTO t1 VALUES(9,NULL);
INSERT INTO t1 VALUES(5,NULL);
INSERT INTO t1 VALUES(123,NULL);
INSERT INTO t1 VALUES(-10,NULL);
CREATE UNIQUE INDEX t1b ON t1(b);
}
execsql_status {
SELECT a FROM t1 WHERE b IS NULL ORDER BY a;
}
} {-10 1 5 9 123 sort}
do_test tkt3824-1.2 {
execsql_status {
SELECT a FROM t1 WHERE b IS NULL ORDER BY b, a;
}
} {-10 1 5 9 123 sort}
do_test tkt3824-2.1 {
db eval {
CREATE TABLE t2(a,b,c);
INSERT INTO t2 VALUES(1,1,NULL);
INSERT INTO t2 VALUES(9,2,NULL);
INSERT INTO t2 VALUES(5,2,NULL);
INSERT INTO t2 VALUES(123,3,NULL);
INSERT INTO t2 VALUES(-10,3,NULL);
CREATE UNIQUE INDEX t2bc ON t2(b,c);
}
execsql_status {
SELECT a FROM t2 WHERE b=2 AND c IS NULL ORDER BY a;
}
} {5 9 sort}
do_test tkt3824-2.2 {
execsql_status {
SELECT a FROM t2 WHERE b=2 AND c IS NULL ORDER BY b, a;
}
} {5 9 sort}
do_test tkt3824-2.3 {
lsort [execsql_status {
SELECT a FROM t2 WHERE b=2 AND c IS NULL ORDER BY b;
}]
} {5 9 sort}
do_test tkt3824-3.1 {
db eval {
CREATE TABLE t3(x,y);
INSERT INTO t3 SELECT a, b FROM t1;
INSERT INTO t3 VALUES(234,567);
CREATE UNIQUE INDEX t3y ON t3(y);
DELETE FROM t3 WHERE y IS NULL;
SELECT * FROM t3;
}
} {234 567}
finish_test