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Overview
Comment: | Backport the query planner enhancement of [952f5e8c69904] to the 3.7.2 branch. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | branch-3.7.2 |
Files: | files | file ages | folders |
SHA1: |
440d995661c961257ca15833ab94c7ec |
User & Date: | drh 2011-03-04 01:23:26.302 |
Context
2011-03-09
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22:09 | Backport the OP_Next and OP_Prev for UNIQUE indices patch from checkin [f000c9b2b7] on the trunk. (check-in: 2d55234ea3 user: drh tags: branch-3.7.2) | |
2011-03-04
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01:23 | Backport the query planner enhancement of [952f5e8c69904] to the 3.7.2 branch. (check-in: 440d995661 user: drh tags: branch-3.7.2) | |
2011-02-12
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14:23 | Fix the expected output on tests so that it corresponds to the new query planner results. All of veryquick.test is now passing with SQLITE_ENABLE_STAT2. (check-in: f2a8b5ccfb user: drh tags: branch-3.7.2) | |
Changes
Changes to src/where.c.
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4607 4608 4609 4610 4611 4612 4613 | } /* Conditions under which this table becomes the best so far: ** ** (1) The table must not depend on other tables that have not ** yet run. ** | | | > | 4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629 4630 4631 4632 4633 4634 4635 4636 4637 4638 | } /* Conditions under which this table becomes the best so far: ** ** (1) The table must not depend on other tables that have not ** yet run. ** ** (2) A full-table-scan plan cannot supercede indexed plan unless ** the full-table-scan is an "optimal" plan as defined above. ** ** (3) All tables have an INDEXED BY clause or this table lacks an ** INDEXED BY clause or this table uses the specific ** index specified by its INDEXED BY clause. This rule ensures ** that a best-so-far is always selected even if an impossible ** combination of INDEXED BY clauses are given. The error ** will be detected and relayed back to the application later. ** The NEVER() comes about because rule (2) above prevents ** An indexable full-table-scan from reaching rule (3). ** ** (4) The plan cost must be lower than prior plans or else the ** cost must be the same and the number of rows must be lower. */ if( (sCost.used¬Ready)==0 /* (1) */ && (bestJ<0 || (notIndexed&m)!=0 /* (2) */ || (bestPlan.plan.wsFlags & WHERE_NOT_FULLSCAN)==0 || (sCost.plan.wsFlags & WHERE_NOT_FULLSCAN)!=0) && (nUnconstrained==0 || pTabItem->pIndex==0 /* (3) */ || NEVER((sCost.plan.wsFlags & WHERE_NOT_FULLSCAN)!=0)) && (bestJ<0 || sCost.rCost<bestPlan.rCost /* (4) */ || (sCost.rCost<=bestPlan.rCost && sCost.plan.nRow<bestPlan.plan.nRow)) ){ |
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Added test/analyze6.test.
> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 | # 2011 March 3 # # 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 for SQLite library. The focus of the tests # in this file a corner-case query planner optimization involving the # join order of two tables of different sizes. # set testdir [file dirname $argv0] source $testdir/tester.tcl ifcapable !stat2 { finish_test return } set testprefix analyze6 proc eqp {sql {db db}} { uplevel execsql [list "EXPLAIN QUERY PLAN $sql"] $db } do_test analyze6-1.0 { db eval { CREATE TABLE cat(x INT); CREATE UNIQUE INDEX catx ON cat(x); /* Give cat 16 unique integers */ INSERT INTO cat VALUES(1); INSERT INTO cat VALUES(2); INSERT INTO cat SELECT x+2 FROM cat; INSERT INTO cat SELECT x+4 FROM cat; INSERT INTO cat SELECT x+8 FROM cat; CREATE TABLE ev(y INT); CREATE INDEX evy ON ev(y); /* ev will hold 32 copies of 16 integers found in cat */ INSERT INTO ev SELECT x FROM cat; INSERT INTO ev SELECT x FROM cat; INSERT INTO ev SELECT y FROM ev; INSERT INTO ev SELECT y FROM ev; INSERT INTO ev SELECT y FROM ev; INSERT INTO ev SELECT y FROM ev; ANALYZE; SELECT count(*) FROM cat; SELECT count(*) FROM ev; } } {16 512} # The lowest cost plan is to scan CAT and for each integer there, do a single # lookup of the first corresponding entry in EV then read off the equal values # in EV. (Prior to the 2011-03-04 enhancement to where.c, this query would # have used EV for the outer loop instead of CAT - which was about 3x slower.) # do_test analyze6-1.1 { eqp {SELECT count(*) FROM ev, cat WHERE x=y} } {0 0 1 {SCAN TABLE cat (~16 rows)} 0 1 0 {SEARCH TABLE ev USING COVERING INDEX evy (y=?) (~32 rows)}} # The same plan is chosen regardless of the order of the tables in the # FROM clause. # do_test analyze6-1.2 { eqp {SELECT count(*) FROM cat, ev WHERE x=y} } {0 0 0 {SCAN TABLE cat (~16 rows)} 0 1 1 {SEARCH TABLE ev USING COVERING INDEX evy (y=?) (~32 rows)}} finish_test |