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Overview
Comment: | Rollback some of the previous changes in the branch such that the estimated row sizes are now only used as a tie-breaker for index scans. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | row-size-est |
Files: | files | file ages | folders |
SHA1: |
65553ff34b41e54d129ff2fee96be714 |
User & Date: | drh 2013-10-08 20:42:41.270 |
Context
2013-10-08
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22:25 | Fix test cases for the new information in PRAGMA index_list. (check-in: dd03be1065 user: drh tags: row-size-est) | |
20:42 | Rollback some of the previous changes in the branch such that the estimated row sizes are now only used as a tie-breaker for index scans. (check-in: 65553ff34b user: drh tags: row-size-est) | |
20:01 | Use #ifdefs to omit unused code in the columnType() routine depending on compile-time options. (check-in: 3fd5e33217 user: drh tags: row-size-est) | |
Changes
Changes to src/where.c.
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4334 4335 4336 4337 4338 4339 4340 | pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ? pNew->aLTerm[pNew->nLTerm-2] : 0; } if( pNew->wsFlags & WHERE_COLUMN_RANGE ){ /* Adjust nOut and rRun for STAT3 range values */ assert( pNew->nOut==saved_nOut ); whereRangeScanEst(pParse, pBuilder, pBtm, pTop, pNew); | < < < < < < | 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 | pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ? pNew->aLTerm[pNew->nLTerm-2] : 0; } if( pNew->wsFlags & WHERE_COLUMN_RANGE ){ /* Adjust nOut and rRun for STAT3 range values */ assert( pNew->nOut==saved_nOut ); whereRangeScanEst(pParse, pBuilder, pBtm, pTop, pNew); } #ifdef SQLITE_ENABLE_STAT3_OR_STAT4 if( nInMul==0 && pProbe->nSample && pNew->u.btree.nEq<=pProbe->nSampleCol && OptimizationEnabled(db, SQLITE_Stat3) ){ |
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4370 4371 4372 4373 4374 4375 4376 | #endif if( (pNew->wsFlags & (WHERE_IDX_ONLY|WHERE_IPK))==0 ){ /* Each row involves a step of the index, then a binary search of ** the main table */ pNew->rRun = sqlite3LogEstAdd(pNew->rRun,rLogSize>27 ? rLogSize-17 : 10); } /* Step cost for each output row */ | | | 4364 4365 4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376 4377 4378 | #endif if( (pNew->wsFlags & (WHERE_IDX_ONLY|WHERE_IPK))==0 ){ /* Each row involves a step of the index, then a binary search of ** the main table */ pNew->rRun = sqlite3LogEstAdd(pNew->rRun,rLogSize>27 ? rLogSize-17 : 10); } /* Step cost for each output row */ pNew->rRun = sqlite3LogEstAdd(pNew->rRun, pNew->nOut); whereLoopOutputAdjust(pBuilder->pWC, pNew, pSrc->iCursor); rc = whereLoopInsert(pBuilder, pNew); if( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 && pNew->u.btree.nEq<(pProbe->nColumn + (pProbe->zName!=0)) ){ whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nInMul+nIn); } |
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4534 4535 4536 4537 4538 4539 4540 | pNew->u.btree.pIndex = 0; pNew->nLTerm = 1; pNew->aLTerm[0] = pTerm; /* TUNING: One-time cost for computing the automatic index is ** approximately 7*N*log2(N) where N is the number of rows in ** the table being indexed. */ pNew->rSetup = rLogSize + rSize + 28; assert( 28==sqlite3LogEst(7) ); | < | | 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543 4544 4545 4546 4547 | pNew->u.btree.pIndex = 0; pNew->nLTerm = 1; pNew->aLTerm[0] = pTerm; /* TUNING: One-time cost for computing the automatic index is ** approximately 7*N*log2(N) where N is the number of rows in ** the table being indexed. */ pNew->rSetup = rLogSize + rSize + 28; assert( 28==sqlite3LogEst(7) ); /* TUNING: Each index lookup yields 20 rows in the table. This ** is more than the usual guess of 10 rows, since we have no way ** of knowning how selective the index will ultimately be. It would ** not be unreasonable to make this value much larger. */ pNew->nOut = 43; assert( 43==sqlite3LogEst(20) ); pNew->rRun = sqlite3LogEstAdd(rLogSize,pNew->nOut); pNew->wsFlags = WHERE_AUTO_INDEX; pNew->prereq = mExtra | pTerm->prereqRight; rc = whereLoopInsert(pBuilder, pNew); } } } #endif /* SQLITE_OMIT_AUTOMATIC_INDEX */ |
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4575 4576 4577 4578 4579 4580 4581 | pNew->wsFlags = WHERE_IPK; /* Full table scan */ pNew->iSortIdx = b ? iSortIdx : 0; /* TUNING: Cost of full table scan is 3*(N + log2(N)). ** + The extra 3 factor is to encourage the use of indexed lookups ** over full scans. FIXME */ | | > | | | | > < | 4568 4569 4570 4571 4572 4573 4574 4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586 4587 4588 4589 4590 4591 4592 4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603 4604 4605 4606 4607 4608 4609 4610 4611 4612 4613 4614 4615 | pNew->wsFlags = WHERE_IPK; /* Full table scan */ pNew->iSortIdx = b ? iSortIdx : 0; /* TUNING: Cost of full table scan is 3*(N + log2(N)). ** + The extra 3 factor is to encourage the use of indexed lookups ** over full scans. FIXME */ pNew->rRun = sqlite3LogEstAdd(rSize,rLogSize) + 16; whereLoopOutputAdjust(pWC, pNew, pSrc->iCursor); rc = whereLoopInsert(pBuilder, pNew); pNew->nOut = rSize; if( rc ) break; }else{ Bitmask m = pSrc->colUsed & ~columnsInIndex(pProbe); pNew->wsFlags = (m==0) ? (WHERE_IDX_ONLY|WHERE_INDEXED) : WHERE_INDEXED; /* Full scan via index */ if( b || ( m==0 && pProbe->bUnordered==0 && pProbe->szIdxRow<pTab->szTabRow && (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 && sqlite3GlobalConfig.bUseCis && OptimizationEnabled(pWInfo->pParse->db, SQLITE_CoverIdxScan) ) ){ pNew->iSortIdx = b ? iSortIdx : 0; if( m==0 ){ /* TUNING: Cost of a covering index scan is K*(N + log2(N)). ** + The extra factor K of between 1.1 and 3.0 that depends ** on the relative sizes of the table and the index. K ** is smaller for smaller indices, thus favoring them. */ pNew->rRun = sqlite3LogEstAdd(rSize,rLogSize) + 1 + (15*pProbe->szIdxRow)/pTab->szTabRow; }else{ assert( b!=0 ); /* TUNING: Cost of scanning a non-covering index is (N+1)*log2(N) ** which we will simplify to just N*log2(N) */ pNew->rRun = rSize + rLogSize; } whereLoopOutputAdjust(pWC, pNew, pSrc->iCursor); rc = whereLoopInsert(pBuilder, pNew); pNew->nOut = rSize; if( rc ) break; } } |
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4779 4780 4781 4782 4783 4784 4785 | pNew->u.vtab.idxNum = pIdxInfo->idxNum; pNew->u.vtab.needFree = pIdxInfo->needToFreeIdxStr; pIdxInfo->needToFreeIdxStr = 0; pNew->u.vtab.idxStr = pIdxInfo->idxStr; pNew->u.vtab.isOrdered = (u8)((pIdxInfo->nOrderBy!=0) && pIdxInfo->orderByConsumed); pNew->rSetup = 0; | | | 4773 4774 4775 4776 4777 4778 4779 4780 4781 4782 4783 4784 4785 4786 4787 | pNew->u.vtab.idxNum = pIdxInfo->idxNum; pNew->u.vtab.needFree = pIdxInfo->needToFreeIdxStr; pIdxInfo->needToFreeIdxStr = 0; pNew->u.vtab.idxStr = pIdxInfo->idxStr; pNew->u.vtab.isOrdered = (u8)((pIdxInfo->nOrderBy!=0) && pIdxInfo->orderByConsumed); pNew->rSetup = 0; pNew->rRun = sqlite3LogEstFromDouble(pIdxInfo->estimatedCost); /* TUNING: Every virtual table query returns 25 rows */ pNew->nOut = 46; assert( 46==sqlite3LogEst(25) ); whereLoopInsert(pBuilder, pNew); if( pNew->u.vtab.needFree ){ sqlite3_free(pNew->u.vtab.idxStr); pNew->u.vtab.needFree = 0; } |
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5272 5273 5274 5275 5276 5277 5278 | if( pWInfo->pOrderBy==0 || nRowEst==0 ){ aFrom[0].isOrderedValid = 1; }else{ /* TUNING: Estimated cost of sorting is 48*N*log2(N) where N is the ** number of output rows. The 48 is the expected size of a row to sort. ** FIXME: compute a better estimate of the 48 multiplier based on the ** result set expressions. */ | | | 5266 5267 5268 5269 5270 5271 5272 5273 5274 5275 5276 5277 5278 5279 5280 | if( pWInfo->pOrderBy==0 || nRowEst==0 ){ aFrom[0].isOrderedValid = 1; }else{ /* TUNING: Estimated cost of sorting is 48*N*log2(N) where N is the ** number of output rows. The 48 is the expected size of a row to sort. ** FIXME: compute a better estimate of the 48 multiplier based on the ** result set expressions. */ rSortCost = nRowEst + estLog(nRowEst); WHERETRACE(0x002,("---- sort cost=%-3d\n", rSortCost)); } /* Compute successively longer WherePaths using the previous generation ** of WherePaths as the basis for the next. Keep track of the mxChoice ** best paths at each generation */ for(iLoop=0; iLoop<nLoop; iLoop++){ |
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Changes to test/select1.test.
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538 539 540 541 542 543 544 | SELECT * FROM test1 a, test1 b LIMIT 1 } } {a.f1 11 a.f2 22 b.f1 11 b.f2 22} do_test select1-6.9.7 { set x [execsql2 { SELECT * FROM test1 a, (select 5, 6) LIMIT 1 }] | | | 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 | SELECT * FROM test1 a, test1 b LIMIT 1 } } {a.f1 11 a.f2 22 b.f1 11 b.f2 22} do_test select1-6.9.7 { set x [execsql2 { SELECT * FROM test1 a, (select 5, 6) LIMIT 1 }] regsub -all {sq_[0-9a-fA-F_]+} $x {subquery} x set x } {a.f1 11 a.f2 22 sqlite_subquery.5 5 sqlite_subquery.6 6} do_test select1-6.9.8 { set x [execsql2 { SELECT * FROM test1 a, (select 5 AS x, 6 AS y) AS b LIMIT 1 }] regsub -all {subquery_[0-9a-fA-F]+_} $x {subquery} x |
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Changes to test/where9.test.
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777 778 779 780 781 782 783 | catchsql { UPDATE t1 INDEXED BY t1b SET a=a+100 WHERE (+b IS NULL AND c NOT NULL AND d NOT NULL) OR (b NOT NULL AND c IS NULL AND d NOT NULL) OR (b NOT NULL AND c NOT NULL AND d IS NULL) } } {1 {no query solution}} | > > > > > > > > > > > | > > > > > > > > > | 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 | catchsql { UPDATE t1 INDEXED BY t1b SET a=a+100 WHERE (+b IS NULL AND c NOT NULL AND d NOT NULL) OR (b NOT NULL AND c IS NULL AND d NOT NULL) OR (b NOT NULL AND c NOT NULL AND d IS NULL) } } {1 {no query solution}} ifcapable stat4||stat3 { # When STAT3 is enabled, the "b NOT NULL" terms get translated # into b>NULL, which can be satified by the index t1b. It is a very # expensive way to do the query, but it works, and so a solution is possible. do_test where9-6.8.3-stat4 { catchsql { UPDATE t1 INDEXED BY t1b SET a=a+100 WHERE (b IS NULL AND c NOT NULL AND d NOT NULL) OR (b NOT NULL AND c IS NULL AND d NOT NULL) OR (b NOT NULL AND c NOT NULL AND d IS NULL) } } {0 {}} do_test where9-6.8.4-stat4 { catchsql { DELETE FROM t1 INDEXED BY t1b WHERE (b IS NULL AND c NOT NULL AND d NOT NULL) OR (b NOT NULL AND c IS NULL AND d NOT NULL) OR (b NOT NULL AND c NOT NULL AND d IS NULL) } } {0 {}} } else { do_test where9-6.8.3 { catchsql { UPDATE t1 INDEXED BY t1b SET a=a+100 WHERE (b IS NULL AND c NOT NULL AND d NOT NULL) OR (b NOT NULL AND c IS NULL AND d NOT NULL) OR (b NOT NULL AND c NOT NULL AND d IS NULL) } |
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