From: dan Date: Tue, 21 Nov 2017 19:22:45 +0000 (+0000) Subject: Update the omit-table-from-left-join optimization so that it can omit tables X-Git-Tag: version-3.22.0~186^2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fheads%2Fleft-join-optimization;p=thirdparty%2Fsqlite.git Update the omit-table-from-left-join optimization so that it can omit tables from the middle of the join as well as the end. FossilOrigin-Name: 618ca9fe53d8d2d7b4f368e6ee404d5fceeecac0d689f32ab62af8a6cbb37401 --- diff --git a/manifest b/manifest index ace7d54144..cd6879f39b 100644 --- a/manifest +++ b/manifest @@ -1,5 +1,5 @@ -C Fix\sa\sproblem\spreventing\sthe\splanner\sfrom\sidentifying\sscans\sthat\svisit\sat\smost\none\srow\sin\scases\swhere\sthat\sproperty\sis\sguaranteed\sby\sa\sunique,\snot-null,\nnon-IPK\scolumn\sthat\sis\sthe\sleftmost\sin\sits\stable. -D 2017-11-20T15:46:10.484 +C Update\sthe\somit-table-from-left-join\soptimization\sso\sthat\sit\scan\somit\stables\nfrom\sthe\smiddle\sof\sthe\sjoin\sas\swell\sas\sthe\send. +D 2017-11-21T19:22:45.416 F Makefile.in b142eb20482922153ebc77b261cdfd0a560ed05a81e9f6d9a2b0e8192922a1d2 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434 F Makefile.msc a55372a22454e742ba7c8f6edf05b83213ec01125166ad7dcee0567e2f7fc81b @@ -553,7 +553,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9 F src/wal.c beeb71e4eab65dbf0d95f2717efc6ca3c0f5b3090ce67f3de63828f39a6ff053 F src/wal.h 8de5d2d3de0956d6f6cb48c83a4012d5f227b8fe940f3a349a4b7e85ebcb492a F src/walker.c da987a20d40145c0a03c07d8fefcb2ed363becc7680d0500d9c79915591f5b1f -F src/where.c e729f477523e3394892951347f57da1471a94a601133c19efd2573903e60a4a2 +F src/where.c 9742731e325768332d67df217eb636556c8605f895d518ee61e4d13029f8aed8 F src/whereInt.h 82c04c5075308abbac59180c8bad5ecb45b07453981f60a53f3c7dee21e1e971 F src/wherecode.c 611fcabd05592ed2febd7d182f9621425b0466c5232d70e0981c842d429356d5 F src/whereexpr.c 427ea8e96ec24f2a7814c67b8024ad664a9c7656264c4566c34743cb23186e46 @@ -983,7 +983,7 @@ F test/ioerr4.test f130fe9e71008577b342b8874d52984bd04ede2c F test/ioerr5.test 2edfa4fb0f896f733071303b42224df8bedd9da4 F test/ioerr6.test a395a6ab144b26a9e3e21059a1ab6a7149cca65b F test/join.test 442c462eea85cf065d70a663c626b780a95af6e11585d909bb63b87598afe678 -F test/join2.test 770a9b6c9f0e91590a102bae707727bce6103b8ad478cea077b2ac126d0698e8 +F test/join2.test ac70b2b79ac593550d1d6f15e9bb3693dd71826b496e84f15166c5053fa518e6 F test/join3.test 6f0c774ff1ba0489e6c88a3e77b9d3528fb4fda0 F test/join4.test 1a352e4e267114444c29266ce79e941af5885916 F test/join5.test bc98ea4b4e5003f5b1453701ebb8cd7d1c01a550 @@ -1677,8 +1677,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0 -P ee840a7669dd462af072625232ea4238198c9b94e1873f361c45f3b0985456f3 bff5dcfd2b29ee4834258914410a5dee69ec2727dd254053e3ebaf5090937694 -R e3d55f8947932d938e221f1f7209d770 -T +closed bff5dcfd2b29ee4834258914410a5dee69ec2727dd254053e3ebaf5090937694 +P 7fdb1e2ac2040dc47800a224d33a5c95d55200c480d46fedec1e97fb4f089ef7 +R 77239b01fe37a025cc689347a6c626c1 +T *branch * left-join-optimization +T *sym-left-join-optimization * +T -sym-trunk * U dan -Z 0d562170c07312a10559bcbda1122c53 +Z 55e1c0e690d530335519db505e442adf diff --git a/manifest.uuid b/manifest.uuid index 258ed7d3a3..ea81b36077 100644 --- a/manifest.uuid +++ b/manifest.uuid @@ -1 +1 @@ -7fdb1e2ac2040dc47800a224d33a5c95d55200c480d46fedec1e97fb4f089ef7 \ No newline at end of file +618ca9fe53d8d2d7b4f368e6ee404d5fceeecac0d689f32ab62af8a6cbb37401 \ No newline at end of file diff --git a/src/where.c b/src/where.c index 955b9450ef..0ced477da4 100644 --- a/src/where.c +++ b/src/where.c @@ -4677,35 +4677,73 @@ WhereInfo *sqlite3WhereBegin( } } #endif - /* Attempt to omit tables from the join that do not effect the result */ + + /* Attempt to omit tables from the join that do not affect the result. + ** For a table to not affect the result, the following must be true: + ** + ** 1) The query must not be an aggregate. + ** 2) The table must be the RHS of a LEFT JOIN. + ** 3) Either the query must be DISTINCT, or else the ON or USING clause + ** must contain a constraint that limits the scan of the table to + ** at most a single row. + ** 4) The table must not be referenced by any part of the query apart + ** from its own USING or ON clause. + ** + ** For example, given: + ** + ** CREATE TABLE t1(ipk INTEGER PRIMARY KEY, v1); + ** CREATE TABLE t2(ipk INTEGER PRIMARY KEY, v2); + ** CREATE TABLE t3(ipk INTEGER PRIMARY KEY, v3); + ** + ** then table t2 can be omitted from the following: + ** + ** SELECT v1, v3 FROM t1 + ** LEFT JOIN t2 USING (t1.ipk=t2.ipk) + ** LEFT JOIN t3 USING (t1.ipk=t3.ipk) + ** + ** or from: + ** + ** SELECT DISTINCT v1, v3 FROM t1 + ** LEFT JOIN t2 + ** LEFT JOIN t3 USING (t1.ipk=t3.ipk) + */ if( pWInfo->nLevel>=2 - && pResultSet!=0 + && pResultSet!=0 /* guarantees condition (1) above */ && OptimizationEnabled(db, SQLITE_OmitNoopJoin) ){ + int i; Bitmask tabUsed = sqlite3WhereExprListUsage(pMaskSet, pResultSet); if( sWLB.pOrderBy ){ tabUsed |= sqlite3WhereExprListUsage(pMaskSet, sWLB.pOrderBy); } - while( pWInfo->nLevel>=2 ){ + for(i=pWInfo->nLevel-1; i>=1; i--){ WhereTerm *pTerm, *pEnd; - pLoop = pWInfo->a[pWInfo->nLevel-1].pWLoop; - if( (pWInfo->pTabList->a[pLoop->iTab].fg.jointype & JT_LEFT)==0 ) break; + struct SrcList_item *pItem; + pLoop = pWInfo->a[i].pWLoop; + pItem = &pWInfo->pTabList->a[pLoop->iTab]; + if( (pItem->fg.jointype & JT_LEFT)==0 ) continue; if( (wctrlFlags & WHERE_WANT_DISTINCT)==0 && (pLoop->wsFlags & WHERE_ONEROW)==0 ){ - break; + continue; } - if( (tabUsed & pLoop->maskSelf)!=0 ) break; + if( (tabUsed & pLoop->maskSelf)!=0 ) continue; pEnd = sWLB.pWC->a + sWLB.pWC->nTerm; for(pTerm=sWLB.pWC->a; pTermprereqAll & pLoop->maskSelf)!=0 - && !ExprHasProperty(pTerm->pExpr, EP_FromJoin) - ){ - break; + if( (pTerm->prereqAll & pLoop->maskSelf)!=0 ){ + if( !ExprHasProperty(pTerm->pExpr, EP_FromJoin) + || pTerm->pExpr->iRightJoinTable!=pItem->iCursor + ){ + break; + } } } - if( pTerm drop loop %c not used\n", pLoop->cId)); + if( i!=pWInfo->nLevel-1 ){ + int nByte = (pWInfo->nLevel-1-i) * sizeof(WhereLevel); + memmove(&pWInfo->a[i], &pWInfo->a[i+1], nByte); + } pWInfo->nLevel--; nTabList--; } @@ -4990,7 +5028,8 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){ addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin); VdbeCoverage(v); assert( (ws & WHERE_IDX_ONLY)==0 || (ws & WHERE_INDEXED)!=0 ); if( (ws & WHERE_IDX_ONLY)==0 ){ - sqlite3VdbeAddOp1(v, OP_NullRow, pTabList->a[i].iCursor); + assert( pLevel->iTabCur==pTabList->a[pLevel->iFrom].iCursor ); + sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iTabCur); } if( (ws & WHERE_INDEXED) || ((ws & WHERE_MULTI_OR) && pLevel->u.pCovidx) diff --git a/test/join2.test b/test/join2.test index 65a0ca266b..9fdcef1783 100644 --- a/test/join2.test +++ b/test/join2.test @@ -123,4 +123,52 @@ do_eqp_test 3.2 { 0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)} } +#------------------------------------------------------------------------- +# Test that tables other than the rightmost can be omitted from a +# LEFT JOIN query. +# +do_execsql_test 4.0 { + CREATE TABLE c1(k INTEGER PRIMARY KEY, v1); + CREATE TABLE c2(k INTEGER PRIMARY KEY, v2); + CREATE TABLE c3(k INTEGER PRIMARY KEY, v3); + + INSERT INTO c1 VALUES(1, 2); + INSERT INTO c2 VALUES(2, 3); + INSERT INTO c3 VALUES(3, 'v3'); + + INSERT INTO c1 VALUES(111, 1112); + INSERT INTO c2 VALUES(112, 1113); + INSERT INTO c3 VALUES(113, 'v1113'); +} +do_execsql_test 4.1.1 { + SELECT v1, v3 FROM c1 LEFT JOIN c2 ON (c2.k=v1) LEFT JOIN c3 ON (c3.k=v2); +} {2 v3 1112 {}} +do_execsql_test 4.1.2 { + SELECT v1, v3 FROM c1 LEFT JOIN c2 ON (c2.k=v1) LEFT JOIN c3 ON (c3.k=v1+1); +} {2 v3 1112 {}} + +do_execsql_test 4.1.3 { + SELECT DISTINCT v1, v3 FROM c1 LEFT JOIN c2 LEFT JOIN c3 ON (c3.k=v1+1); +} {2 v3 1112 {}} + +do_execsql_test 4.1.4 { + SELECT v1, v3 FROM c1 LEFT JOIN c2 LEFT JOIN c3 ON (c3.k=v1+1); +} {2 v3 2 v3 1112 {} 1112 {}} + +do_eqp_test 4.2.1 { + SELECT v1, v3 FROM c1 LEFT JOIN c2 ON (c2.k=v1) LEFT JOIN c3 ON (c3.k=v2); +} { + 0 0 0 {SCAN TABLE c1} + 0 1 1 {SEARCH TABLE c2 USING INTEGER PRIMARY KEY (rowid=?)} + 0 2 2 {SEARCH TABLE c3 USING INTEGER PRIMARY KEY (rowid=?)} +} +do_eqp_test 4.2.2 { + SELECT v1, v3 FROM c1 LEFT JOIN c2 ON (c2.k=v1) LEFT JOIN c3 ON (c3.k=v1+1); +} { + 0 0 0 {SCAN TABLE c1} + 0 1 2 {SEARCH TABLE c3 USING INTEGER PRIMARY KEY (rowid=?)} +} + + + finish_test