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If a table is on the rhs of a LEFT JOIN, include only terms from the joins ON(...) clause in the cursor-hint passed via OP_CursorHint.

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FossilOrigin-Name: 2a2346b04235c6d0b7a8e64c92ee31018285c29f
This commit is contained in:
dan
2016-06-17 14:33:32 +00:00
parent 3480bfdae9
commit b324cf756e
4 changed files with 142 additions and 12 deletions
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16
manifest
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@ -1,5 +1,5 @@
C Add\sa\smissing\sOP_ColumnsUsed\sopcode\sto\scode\sfor\sexpressions\slike\s"?\sIN\s(SELECT\s...)"\sin\scases\swhere\sexpression\scan\suse\san\sindex\sthat\smay\scontain\sNULL\svalues.
D 2016-06-16T17:14:02.375
C If\sa\stable\sis\son\sthe\srhs\sof\sa\sLEFT\sJOIN,\sinclude\sonly\sterms\sfrom\sthe\sjoins\sON(...)\sclause\sin\sthe\scursor-hint\spassed\svia\sOP_CursorHint.
D 2016-06-17T14:33:32.727
F Makefile.in f3f7d2060ce03af4584e711ef3a626ef0b1d6340
F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
F Makefile.msc 50149765ef72f4e652b9a0f1f6462c4784bb9423
@ -464,7 +464,7 @@ F src/wal.h 2f7c831cf3b071fa548bf2d5cac640846a7ff19c
F src/walker.c 0f142b5bd3ed2041fc52d773880748b212e63354
F src/where.c 74f0798525b6306682d7234f230ea93f86959b9b
F src/whereInt.h e5b939701a7ceffc5a3a8188a37f9746416ebcd0
F src/wherecode.c ba71a4e4bada29aa9842200e6299714bf18c812c
F src/wherecode.c b9d5f7d8ebed2e09376fd785a111ffd9dfd59ffc
F src/whereexpr.c c32d47085dbaca0b8fd013210f56693c7d220d48
F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
F test/affinity2.test a6d901b436328bd67a79b41bb0ac2663918fe3bd
@ -617,6 +617,7 @@ F test/cse.test 277350a26264495e86b1785f34d2d0c8600e021c
F test/csv01.test 0929a9ce47021519512be92861f29e32d2538e5f
F test/ctime.test 7bd009071e242aac4f18521581536b652b789a47
F test/cursorhint.test 7bc346788390475e77a345da2b92270d04d35856
F test/cursorhint2.test 532fdc678653f73e30770b59af0a47f9af0124ee
F test/date.test 984ac1e3e5e031386866f034006148d3972b4a65
F test/dbstatus.test 8de104bb5606f19537d23cd553b41349b5ab1204
F test/dbstatus2.test e93ab03bfae6d62d4d935f20de928c19ca0ed0ab
@ -1501,7 +1502,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
P 48b555c42de1cbc031fb6c2c93ef170e491c7d76
R 7c056b92500e212b6fa7144618e1e6e0
P 0b1579caf06a2c42433b8bc9dc28c9ad381aa07c
R 2d1831333befb414525bf922ba35c127
T *branch * cursor-hints
T *sym-cursor-hints *
T -sym-trunk *
U dan
Z 6cf13efbb72ea4474e244da36e8952f1
Z b45fbbd37d7e68d5f1357e6143b6a1f1

2
manifest.uuid
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@ -1 +1 @@
0b1579caf06a2c42433b8bc9dc28c9ad381aa07c
2a2346b04235c6d0b7a8e64c92ee31018285c29f

33
src/wherecode.c
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@ -678,6 +678,7 @@ static int codeCursorHintFixExpr(Walker *pWalker, Expr *pExpr){
** Insert an OP_CursorHint instruction if it is appropriate to do so.
*/
static void codeCursorHint(
struct SrcList_item *pTabItem, /* FROM clause item */
WhereInfo *pWInfo, /* The where clause */
WhereLevel *pLevel, /* Which loop to provide hints for */
WhereTerm *pEndRange /* Hint this end-of-scan boundary term if not NULL */
@ -708,7 +709,31 @@ static void codeCursorHint(
pTerm = &pWC->a[i];
if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
if( pTerm->prereqAll & pLevel->notReady ) continue;
/* Any terms specified as part of the ON(...) clause for any LEFT
** JOIN for which the current table is not the rhs are omitted
** from the cursor-hint.
**
** If this table is the rhs of a LEFT JOIN, only terms that were
** specified as part of the ON(...) clause may be included in the
** hint. This is to address the following:
**
** SELECT ... t1 LEFT JOIN t2 ON (t1.a=t2.b) WHERE t2.c IS NULL;
**
** If the (t2.c IS NULL) constraint is pushed down to the cursor, it
** might filter out all rows that match (t1.a=t2.b), causing SQLite
** to add a row of NULL values to the output that should not be
** present (since the ON clause does actually match rows within t2).
*/
if( pTabItem->fg.jointype & JT_LEFT ){
if( !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
|| pTerm->pExpr->iRightJoinTable!=pTabItem->iCursor
){
continue;
}
}else{
if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) continue;
}
/* All terms in pWLoop->aLTerm[] except pEndRange are used to initialize
** the cursor. These terms are not needed as hints for a pure range
@ -742,7 +767,7 @@ static void codeCursorHint(
}
}
#else
# define codeCursorHint(A,B,C) /* No-op */
# define codeCursorHint(A,B,C,D) /* No-op */
#endif /* SQLITE_ENABLE_CURSOR_HINTS */
/*
@ -998,7 +1023,7 @@ Bitmask sqlite3WhereCodeOneLoopStart(
pStart = pEnd;
pEnd = pTerm;
}
codeCursorHint(pWInfo, pLevel, pEnd);
codeCursorHint(pTabItem, pWInfo, pLevel, pEnd);
if( pStart ){
Expr *pX; /* The expression that defines the start bound */
int r1, rTemp; /* Registers for holding the start boundary */
@ -1212,7 +1237,7 @@ Bitmask sqlite3WhereCodeOneLoopStart(
** and store the values of those terms in an array of registers
** starting at regBase.
*/
codeCursorHint(pWInfo, pLevel, pRangeEnd);
codeCursorHint(pTabItem, pWInfo, pLevel, pRangeEnd);
regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);
assert( zStartAff==0 || sqlite3Strlen30(zStartAff)>=nEq );
if( zStartAff ) cEndAff = zStartAff[nEq];
@ -1660,7 +1685,7 @@ Bitmask sqlite3WhereCodeOneLoopStart(
** a pseudo-cursor. No need to Rewind or Next such cursors. */
pLevel->op = OP_Noop;
}else{
codeCursorHint(pWInfo, pLevel, 0);
codeCursorHint(pTabItem, pWInfo, pLevel, 0);
pLevel->op = aStep[bRev];
pLevel->p1 = iCur;
pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);

101
test/cursorhint2.test Normal file
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@ -0,0 +1,101 @@
# 2016 June 17
#
# 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.
#
#***********************************************************************
# This file implements regression tests for SQLite library. The
# focus is on testing that cursor-hints are correct for queries
# involving LEFT JOIN.
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl
set ::testprefix cursorhint2
ifcapable !cursorhints {
finish_test
return
}
proc extract_hints {sql} {
db eval "SELECT tbl_name, rootpage FROM sqlite_master where rootpage" {
set lookup($rootpage) $tbl_name
}
set ret [list]
db eval "EXPLAIN $sql" a {
switch -- $a(opcode) {
OpenRead {
set csr($a(p1)) $lookup($a(p2))
}
CursorHint {
lappend ret $csr($a(p1)) $a(p4)
}
}
}
set ret
}
proc do_extract_hints_test {tn sql ret} {
uplevel [list do_test $tn [list extract_hints $sql] [list {*}$ret]]
}
do_execsql_test 1.0 {
PRAGMA automatic_index = 0;
CREATE TABLE t1(a, b);
CREATE TABLE t2(c, d);
CREATE TABLE t3(e, f);
}
do_extract_hints_test $tn.1.1 {
SELECT * FROM t1 WHERE a=1;
} {
t1 EQ(c0,1)
}
do_extract_hints_test $tn.1.2 {
SELECT * FROM t1 CROSS JOIN t2 ON (a=c) WHERE d IS NULL;
} {
t2 {AND(ISNULL(c1),EQ(r[1],c0))}
}
do_extract_hints_test $tn.1.3 {
SELECT * FROM t1 LEFT JOIN t2 ON (a=c) WHERE d IS NULL;
} {
t2 {EQ(r[2],c0)}
}
do_extract_hints_test $tn.1.4 {
SELECT * FROM t1 LEFT JOIN t2 ON (a=c AND a=10) WHERE d IS NULL;
} {
t2 {AND(EQ(r[2],c0),EQ(r[3],10))}
}
do_extract_hints_test $tn.1.5 {
SELECT * FROM t1 CROSS JOIN t2 ON (a=c AND a=10) WHERE d IS NULL;
} {
t1 EQ(c0,10) t2 {AND(ISNULL(c1),EQ(r[3],c0))}
}
do_extract_hints_test $tn.1.6 {
SELECT * FROM t1 LEFT JOIN t2 ON (a=c) LEFT JOIN t3 ON (d=f);
} {
t2 {EQ(r[2],c0)} t3 {EQ(r[6],c1)}
}
do_extract_hints_test $tn.1.6 {
SELECT * FROM t1 LEFT JOIN t2 ON (a=c AND d=e) LEFT JOIN t3 ON (d=f);
} {
t2 {EQ(r[2],c0)} t3 {EQ(r[6],c1)}
}
finish_test