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Use compile-time options SQLITE_QUERY_PLANNER_LIMIT and

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SQLITE_QUERY_PLANNER_LIMIT_INCR to control the value for
WhereLoopBuilder.iPlanLimit, rather than embedding magic numbers in the
code.

FossilOrigin-Name: 903e501894b2a5dd7055b5154d74d4a47a619f76e66485a4d62b6259f10723d6
This commit is contained in:
drh 2018-09-24 12:37:01 +00:00
parent 7ebb605c0a
commit 6fb5d358a8
4 changed files with 30 additions and 16 deletions
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14
manifest
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@ -1,5 +1,5 @@
C Increase\sthe\sinitial\svalue\sof\sWhereLoopBuilder.iPlanLimit\sto\s20K.\s\sIssue\na\swarning\sif\sthe\siPlanLimit\sreaches\szero.
D 2018-09-24T10:47:33.898
C Use\scompile-time\soptions\sSQLITE_QUERY_PLANNER_LIMIT\sand\nSQLITE_QUERY_PLANNER_LIMIT_INCR\sto\scontrol\sthe\svalue\sfor\nWhereLoopBuilder.iPlanLimit,\srather\sthan\sembedding\smagic\snumbers\sin\sthe\ncode.
D 2018-09-24T12:37:01.477
F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
F Makefile.in 01e95208a78b57d056131382c493c963518f36da4c42b12a97eb324401b3a334
@ -587,8 +587,8 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
F src/wal.c 3f4f653daf234fe713edbcbca3fec2350417d159d28801feabc702a22c4e213f
F src/wal.h 606292549f5a7be50b6227bd685fa76e3a4affad71bb8ac5ce4cb5c79f6a176a
F src/walker.c fb94aadc9099ff9c6506d0a8b88d51266005bcaa265403f3d7caf732a562eb66
F src/where.c 49022d3c155a3af14298459d6990c0c9f096f42afa1edb6d86e8f4ac45a6301e
F src/whereInt.h 2c4d99faf71c35339a33b20d11c5cb8921416a21d6816d830b85df320303e5bd
F src/where.c a54a3d639bcd751d1474deff58e239b2e475a96e1b8f9178aa7864df8782a4e3
F src/whereInt.h f125f29fca80890768e0b2caa14f95db74b2dacd3a122a168f97aa7b64d6968f
F src/wherecode.c 3df0a541373d5f999684d761e4bd700d57adb46c7d39da4e77b767b5adcd5893
F src/whereexpr.c 1b5a5a7876997f65232bbf19c5c1eeb47eb328b8fa5b28c865543052904cde00
F src/window.c a28d8d42c51c7e31136a42f3e245282049d4a9466b36d7bd765772991472df41
@ -1769,7 +1769,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
P 2fd62fccd13e326dbd7dd730112542c6faa56e466bf4f7b8e22ced543031280c
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R 0a5c287a2221a9c37c274db4cfcb24c3
U drh
Z 063489dbcea38420d3799029994c4f5a
Z d1e830ee2a4fd61d34b42065fcc1584a

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@ -1 +1 @@
3dd35f51187574f47f860405309877cdbf9dc5710703dfd98cf98073b771140c
903e501894b2a5dd7055b5154d74d4a47a619f76e66485a4d62b6259f10723d6

10
src/where.c
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@ -3540,17 +3540,11 @@ static int whereLoopAddAll(WhereLoopBuilder *pBuilder){
/* Loop over the tables in the join, from left to right */
pNew = pBuilder->pNew;
whereLoopInit(pNew);
/* Some pathological queries provide an unreasonable number of indexing
** options. The iPlanLimit value prevents these queries from taking up
** too much time in the planner. When iPlanLimit reaches zero, no further
** index+constraint options are considered. Seed iPlanLimit to 20K but
** also add an extra 1K to each table of the join, to ensure that each
** table at least gets 1K opportunities. */
pBuilder->iPlanLimit = 20000;
pBuilder->iPlanLimit = SQLITE_QUERY_PLANNER_LIMIT;
for(iTab=0, pItem=pTabList->a; pItem<pEnd; iTab++, pItem++){
Bitmask mUnusable = 0;
pNew->iTab = iTab;
pBuilder->iPlanLimit += 1000; /* 1000 bonus for each table in the join */
pBuilder->iPlanLimit += SQLITE_QUERY_PLANNER_LIMIT_INCR;
pNew->maskSelf = sqlite3WhereGetMask(&pWInfo->sMaskSet, pItem->iCursor);
if( ((pItem->fg.jointype|priorJointype) & (JT_LEFT|JT_CROSS))!=0 ){
/* This condition is true when pItem is the FROM clause term on the

20
src/whereInt.h
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@ -409,6 +409,26 @@ struct WhereLoopBuilder {
#define SQLITE_BLDF_INDEXED 0x0001 /* An index is used */
#define SQLITE_BLDF_UNIQUE 0x0002 /* All keys of a UNIQUE index used */
/* The WhereLoopBuilder.iPlanLimit is used to limit the number of
** index+constraint combinations the query planner will consider for a
** particular query. If this parameter is unlimited, then certain
** pathological queries can spend excess time in the sqlite3WhereBegin()
** routine. The limit is high enough that is should not impact real-world
** queries.
**
** SQLITE_QUERY_PLANNER_LIMIT is the baseline limit. The limit is
** increased by SQLITE_QUERY_PLANNER_LIMIT_INCR before each term of the FROM
** clause is processed, so that every table in a join is guaranteed to be
** able to propose a some index+constraint combinations even if the initial
** baseline limit was exhausted by prior tables of the join.
*/
#ifndef SQLITE_QUERY_PLANNER_LIMIT
# define SQLITE_QUERY_PLANNER_LIMIT 20000
#endif
#ifndef SQLITE_QUERY_PLANNER_LIMIT_INCR
# define SQLITE_QUERY_PLANNER_LIMIT_INCR 1000
#endif
/*
** The WHERE clause processing routine has two halves. The
** first part does the start of the WHERE loop and the second