From: dan Date: Fri, 27 Jun 2014 20:14:25 +0000 (+0000) Subject: Fix a couple of problems in estimating the number of rows visited by a range query... X-Git-Tag: version-3.8.6~92^2~6 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4e42ba4a356f21306a84a2958ee1a66a7f285cfd;p=thirdparty%2Fsqlite.git Fix a couple of problems in estimating the number of rows visited by a range query that uses a skip-scan. FossilOrigin-Name: 219736f54dcd1448af3400e699f1c20755ac6876 --- diff --git a/manifest b/manifest index 3a8265365f..14dfe69604 100644 --- a/manifest +++ b/manifest @@ -1,5 +1,5 @@ -C Fix\scompilation\sissue\swhen\sSTAT4\sis\snot\senabled. -D 2014-06-26T21:32:09.075 +C Fix\sa\scouple\sof\sproblems\sin\sestimating\sthe\snumber\sof\srows\svisited\sby\sa\srange\squery\sthat\suses\sa\sskip-scan. +D 2014-06-27T20:14:25.215 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f F Makefile.in b03432313a3aad96c706f8164fb9f5307eaf19f5 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23 @@ -289,14 +289,14 @@ F src/vdbeInt.h e6d83e5bfd62fc6685ba1ed6153f7099f82de9f7 F src/vdbeapi.c 0ed6053f947edd0b30f64ce5aeb811872a3450a4 F src/vdbeaux.c e493f38758c4b8f4ca2007cf6a700bd405d192f3 F src/vdbeblob.c 9205ce9d3b064d9600f8418a897fc88b5687d9ac -F src/vdbemem.c 8f28cb5bdd5b8748dba67aab5a07a47386fe40dc +F src/vdbemem.c 3f191d4113805e3c5e875b732c44c9d98bac0595 F src/vdbesort.c 44441d73b08b3a638dcdb725afffb87c6574ad27 F src/vdbetrace.c 6f52bc0c51e144b7efdcfb2a8f771167a8816767 F src/vtab.c 21b932841e51ebd7d075e2d0ad1415dce8d2d5fd F src/wal.c 264df50a1b33124130b23180ded2e2c5663c652a F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4 F src/walker.c 11edb74d587bc87b33ca96a5173e3ec1b8389e45 -F src/where.c 0396f040a1ffe31b1f63673c6cd6c469c5e4ce57 +F src/where.c fea270aeef23f978edac94b5591c74b0bf3ce884 F src/whereInt.h 929c1349b5355fd44f22cee5c14d72b3329c58a6 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2 @@ -829,6 +829,7 @@ F test/shrink.test 8c70f62b6e8eb4d54533de6d65bd06b1b9a17868 F test/sidedelete.test f0ad71abe6233e3b153100f3b8d679b19a488329 F test/skipscan1.test 28c7faa41a0d7265040ecb0a0abd90c0904270b2 F test/skipscan2.test d1d1450952b7275f0b0a3a981f0230532743951a +F test/skipscan5.test 7eb78ace4e7145fb5005d47a8f837701d7027b85 F test/soak.test 0b5b6375c9f4110c828070b826b3b4b0bb65cd5f F test/softheap1.test 40562fe6cac6d9827b7b42b86d45aedf12c15e24 F test/sort.test 0e4456e729e5a92a625907c63dcdedfbe72c5dc5 @@ -1180,7 +1181,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f -P 01dc8102592427b71a18c2cb82301d2266dd59c2 -R 1ded9652c09c1b748cd5e7181ce5016c -U mistachkin -Z b89953846d49961fb37fc288882b8874 +P 74a5454a710e1b7d8575cec2f872e6110aefce17 +R 02edb14d4ef805eea40e69e5acdf39b7 +U dan +Z bd7cb892a5b1d67344c0bf9079bc8afa diff --git a/manifest.uuid b/manifest.uuid index 7e63e6d9db..d621593f3a 100644 --- a/manifest.uuid +++ b/manifest.uuid @@ -1 +1 @@ -74a5454a710e1b7d8575cec2f872e6110aefce17 \ No newline at end of file +219736f54dcd1448af3400e699f1c20755ac6876 \ No newline at end of file diff --git a/src/vdbemem.c b/src/vdbemem.c index 67dea9c282..634c881f2f 100644 --- a/src/vdbemem.c +++ b/src/vdbemem.c @@ -1296,7 +1296,7 @@ int sqlite3Stat4Column( iHdr = getVarint32(a, nHdr); iField = nHdr; for(i=0; iu.btree.pIndex; int nEq = pLoop->u.btree.nEq; sqlite3 *db = pParse->db; - int nLower = 0; - int nUpper = 0; + int nLower = -1; + int nUpper = p->nSample+1; int rc = SQLITE_OK; u8 aff = p->pTable->aCol[ p->aiColumn[nEq] ].affinity; CollSeq *pColl; @@ -2058,9 +2058,11 @@ static int whereRangeSkipScanEst( pColl = sqlite3LocateCollSeq(pParse, p->azColl[nEq]); if( pLower ){ rc = sqlite3Stat4ValueFromExpr(pParse, pLower->pExpr->pRight, aff, &p1); + nLower = 0; } if( pUpper && rc==SQLITE_OK ){ rc = sqlite3Stat4ValueFromExpr(pParse, pUpper->pExpr->pRight, aff, &p2); + nUpper = p2 ? 0 : p->nSample; } if( p1 || p2 ){ @@ -2070,18 +2072,29 @@ static int whereRangeSkipScanEst( rc = sqlite3Stat4Column(db, p->aSample[i].p, p->aSample[i].n, nEq, &pVal); if( rc==SQLITE_OK && p1 ){ int res = sqlite3MemCompare(p1, pVal, pColl); - if( res<=0 ) nLower++; + if( res>=0 ) nLower++; } if( rc==SQLITE_OK && p2 ){ int res = sqlite3MemCompare(p2, pVal, pColl); - if( res<=0 ) nUpper++; + if( res>=0 ) nUpper++; } } - if( p2==0 ) nUpper = p->nSample; nDiff = (nUpper - nLower); if( nDiff<=0 ) nDiff = 1; - pLoop->nOut -= (sqlite3LogEst(p->nSample) - sqlite3LogEst(nDiff)); - *pbDone = 1; + + /* If there is both an upper and lower bound specified, and the + ** comparisons indicate that they are close together, use the fallback + ** method (assume that the scan visits 1/64 of the rows) for estimating + ** the number of rows visited. Otherwise, estimate the number of rows + ** using the method described in the header comment for this function. */ + if( nDiff!=1 || pUpper==0 || pLower==0 ){ + int nAdjust = (sqlite3LogEst(p->nSample) - sqlite3LogEst(nDiff)); + pLoop->nOut -= nAdjust; + *pbDone = 1; + WHERETRACE(0x10, ("range skip-scan regions: %u..%u adjust=%d est=%d\n", + (u32)nLower, (u32)nUpper, nAdjust*-1, pLoop->nOut)); + } + }else{ assert( *pbDone==0 ); } diff --git a/test/skipscan5.test b/test/skipscan5.test new file mode 100644 index 0000000000..b374302f83 --- /dev/null +++ b/test/skipscan5.test @@ -0,0 +1,95 @@ +# 2013-11-13 +# +# 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 tests of the "skip-scan" query strategy. In +# particular it tests that stat4 data can be used by a range query +# that uses the skip-scan approach. +# + +set testdir [file dirname $argv0] +source $testdir/tester.tcl +set testprefix skipscan5 + +ifcapable !stat4 { + finish_test + return +} + +do_execsql_test 1.1 { + CREATE TABLE t1(a INT, b INT, c INT); + CREATE INDEX i1 ON t1(a, b); +} {} + +expr srand(4) +do_test 1.2 { + for {set i 0} {$i < 100} {incr i} { + set a [expr int(rand()*4.0) + 1] + set b [expr int(rand()*20.0) + 1] + execsql { INSERT INTO t1 VALUES($a, $b, NULL) } + } + execsql ANALYZE +} {} + +do_eqp_test 1.3 { + SELECT * FROM t1 WHERE b = 5; +} { + 0 0 0 {SEARCH TABLE t1 USING INDEX i1 (ANY(a) AND b=?)} +} + +do_eqp_test 1.4 { + SELECT * FROM t1 WHERE b > 12 AND b < 16; +} { + 0 0 0 {SEARCH TABLE t1 USING INDEX i1 (ANY(a) AND b>? AND b 2 AND b < 16; +} { + 0 0 0 {SCAN TABLE t1} +} + +do_eqp_test 1.6 { + SELECT * FROM t1 WHERE b > 18 AND b < 25; +} { + 0 0 0 {SEARCH TABLE t1 USING INDEX i1 (ANY(a) AND b>? AND b 18 AND b < 25; +} { + 0 0 0 {SEARCH TABLE t1 USING INDEX i1 (ANY(a) AND b>? AND b 15; +} { + 0 0 0 {SEARCH TABLE t1 USING INDEX i1 (ANY(a) AND b>?)} +} + +do_eqp_test 1.9 { + SELECT * FROM t1 WHERE b > 5; +} { + 0 0 0 {SCAN TABLE t1} +} + +do_eqp_test 1.10 { + SELECT * FROM t1 WHERE b < 5; +} { + 0 0 0 {SEARCH TABLE t1 USING INDEX i1 (ANY(a) AND b