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Overview
Comment: | In cases where stat4 data is available but cannot be used because the rhs of a range constraint is too complex a expression, fall back to using the default estimates for number of rows scanned. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
e06dc6f0c35f87c44292c71677111b74 |
User & Date: | dan 2014-08-25 18:29:38.998 |
Context
2014-08-25
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20:11 | Allow CAST expressions and unary "+" operators to be used in the DEFAULT argument of an ALTER TABLE ADD COLUMN and to be understand on the RHS of range constraints interpreted by STAT3/4. This involves a rewrite of the implementation of the CAST operator. (check-in: 91d8a8d0b7 user: drh tags: trunk) | |
18:29 | In cases where stat4 data is available but cannot be used because the rhs of a range constraint is too complex a expression, fall back to using the default estimates for number of rows scanned. (check-in: e06dc6f0c3 user: dan tags: trunk) | |
11:33 | Remove the pager_lookup() function since it is redundant with sqlite3PagerLookup(). (check-in: 54164ce47c user: drh tags: trunk) | |
Changes
Changes to src/where.c.
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2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 | rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk); if( rc==SQLITE_OK && bOk ){ tRowcnt iNew; whereKeyStats(pParse, p, pRec, 0, a); iNew = a[0] + ((pLower->eOperator & WO_GT) ? a[1] : 0); if( iNew>iLower ) iLower = iNew; nOut--; } } /* If possible, improve on the iUpper estimate using ($P:$U). */ if( pUpper ){ int bOk; /* True if value is extracted from pExpr */ Expr *pExpr = pUpper->pExpr->pRight; assert( (pUpper->eOperator & (WO_LT|WO_LE))!=0 ); rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk); if( rc==SQLITE_OK && bOk ){ tRowcnt iNew; whereKeyStats(pParse, p, pRec, 1, a); iNew = a[0] + ((pUpper->eOperator & WO_LE) ? a[1] : 0); if( iNew<iUpper ) iUpper = iNew; nOut--; } } pBuilder->pRec = pRec; if( rc==SQLITE_OK ){ if( iUpper>iLower ){ nNew = sqlite3LogEst(iUpper - iLower); }else{ nNew = 10; assert( 10==sqlite3LogEst(2) ); } if( nNew<nOut ){ nOut = nNew; } | > > < < < > | 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 | rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk); if( rc==SQLITE_OK && bOk ){ tRowcnt iNew; whereKeyStats(pParse, p, pRec, 0, a); iNew = a[0] + ((pLower->eOperator & WO_GT) ? a[1] : 0); if( iNew>iLower ) iLower = iNew; nOut--; pLower = 0; } } /* If possible, improve on the iUpper estimate using ($P:$U). */ if( pUpper ){ int bOk; /* True if value is extracted from pExpr */ Expr *pExpr = pUpper->pExpr->pRight; assert( (pUpper->eOperator & (WO_LT|WO_LE))!=0 ); rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk); if( rc==SQLITE_OK && bOk ){ tRowcnt iNew; whereKeyStats(pParse, p, pRec, 1, a); iNew = a[0] + ((pUpper->eOperator & WO_LE) ? a[1] : 0); if( iNew<iUpper ) iUpper = iNew; nOut--; pUpper = 0; } } pBuilder->pRec = pRec; if( rc==SQLITE_OK ){ if( iUpper>iLower ){ nNew = sqlite3LogEst(iUpper - iLower); }else{ nNew = 10; assert( 10==sqlite3LogEst(2) ); } if( nNew<nOut ){ nOut = nNew; } WHERETRACE(0x10, ("range scan regions: %u..%u est=%d\n", (u32)iLower, (u32)iUpper, nOut)); } }else{ int bDone = 0; rc = whereRangeSkipScanEst(pParse, pLower, pUpper, pLoop, &bDone); if( bDone ) return rc; } } #else UNUSED_PARAMETER(pParse); UNUSED_PARAMETER(pBuilder); assert( pLower || pUpper ); #endif assert( pUpper==0 || (pUpper->wtFlags & TERM_VNULL)==0 ); nNew = whereRangeAdjust(pLower, nOut); nNew = whereRangeAdjust(pUpper, nNew); /* TUNING: If there is both an upper and lower limit, assume the range is ** reduced by an additional 75%. This means that, by default, an open-ended ** range query (e.g. col > ?) is assumed to match 1/4 of the rows in the |
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Changes to test/analyze9.test.
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1083 1084 1085 1086 1087 1088 1089 1090 1091 | 2 "d=0 AND a='z' AND b='n' AND e<100" {/*t5e (e<?)*/} 3 "d=0 AND e<300" {/*t5d (d=?)*/} 4 "d=0 AND e<200" {/*t5e (e<?)*/} } { do_eqp_test 24.$tn "SeLeCt * FROM t5 WHERE $where" $eqp } finish_test | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 | 2 "d=0 AND a='z' AND b='n' AND e<100" {/*t5e (e<?)*/} 3 "d=0 AND e<300" {/*t5d (d=?)*/} 4 "d=0 AND e<200" {/*t5e (e<?)*/} } { do_eqp_test 24.$tn "SeLeCt * FROM t5 WHERE $where" $eqp } #------------------------------------------------------------------------- # Test that if stat4 data is available but cannot be used because the # rhs of a range constraint is a complex expression, the default estimates # are used instead. ifcapable stat4&&cte { do_execsql_test 25.1 { CREATE TABLE t6(a, b); WITH ints(i,j) AS ( SELECT 1,1 UNION ALL SELECT i+1,j+1 FROM ints WHERE i<100 ) INSERT INTO t6 SELECT * FROM ints; CREATE INDEX aa ON t6(a); CREATE INDEX bb ON t6(b); ANALYZE; } # Term (b<?) is estimated at 25%. Better than (a<30) but not as # good as (a<20). do_eqp_test 25.2.1 { SELECT * FROM t6 WHERE a<30 AND b<? } { 0 0 0 {SEARCH TABLE t6 USING INDEX bb (b<?)} } do_eqp_test 25.2.2 { SELECT * FROM t6 WHERE a<20 AND b<? } { 0 0 0 {SEARCH TABLE t6 USING INDEX aa (a<?)} } # Term (b BETWEEN ? AND ?) is estimated at 1/64. do_eqp_test 25.3.1 { SELECT * FROM t6 WHERE a BETWEEN 5 AND 10 AND b BETWEEN ? AND ? } { 0 0 0 {SEARCH TABLE t6 USING INDEX bb (b>? AND b<?)} } # Term (b BETWEEN ? AND 60) is estimated to return roughly 15 rows - # 60 from (b<=60) multiplied by 0.25 for the b>=? term. Better than # (a<20) but not as good as (a<10). do_eqp_test 25.4.1 { SELECT * FROM t6 WHERE a < 10 AND (b BETWEEN ? AND 60) } { 0 0 0 {SEARCH TABLE t6 USING INDEX aa (a<?)} } do_eqp_test 25.4.2 { SELECT * FROM t6 WHERE a < 20 AND (b BETWEEN ? AND 60) } { 0 0 0 {SEARCH TABLE t6 USING INDEX bb (b>? AND b<?)} } } finish_test |