From 70128c09197b1c2e38db1e1bd207a34b093d3a64 Mon Sep 17 00:00:00 2001 From: drh <> Date: Tue, 6 Dec 2022 00:54:55 +0000 Subject: [PATCH] Highly experimental (and non-working) changes aimed at increasing the number of occasions where a subquery can be implemented using a co-routine rather than being materialized. This is just saving work in progress. FossilOrigin-Name: e7d323c16ee774816c825b8a8e078dda8f38bbbd8d87a101a42739559196f503 --- manifest | 25 +++++++++++++---------- manifest.uuid | 2 +- src/prepare.c | 21 +++++++++++++++++--- src/select.c | 53 ++++++++++++++++++++++++++++++++++++------------- src/sqlite.h.in | 1 + src/update.c | 1 + src/vdbe.h | 1 + 7 files changed, 75 insertions(+), 29 deletions(-) diff --git a/manifest b/manifest index 9b85c87887..f2d7a7cc36 100644 --- a/manifest +++ b/manifest @@ -1,5 +1,5 @@ -C Enhance\sthe\ssqlite3_stmt_scanstatus()\sAPI\sand\sadd\ssqlite3_stmt_scanstatus_v2().\sFor\screation\sof\senhanced\squery\sperformance\sreports. -D 2022-12-05T19:16:23.509 +C Highly\sexperimental\s(and\snon-working)\schanges\saimed\sat\sincreasing\sthe\snumber\nof\soccasions\swhere\sa\ssubquery\scan\sbe\simplemented\susing\sa\sco-routine\srather\nthan\sbeing\smaterialized.\s\sThis\sis\sjust\ssaving\swork\sin\sprogress. +D 2022-12-06T00:54:55.085 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724 @@ -640,14 +640,14 @@ F src/pcache.h 4f87acd914cef5016fae3030343540d75f5b85a1877eed1a2a19b9f284248586 F src/pcache1.c dee95e3cd2b61e6512dc814c5ab76d5eb36f0bfc9441dbb4260fccc0d12bbddc F src/pragma.c 894c2621d35edd4beea9b331cfdb1b42032394420074d2294c8febe548eea8a1 F src/pragma.h e690a356c18e98414d2e870ea791c1be1545a714ba623719deb63f7f226d8bb7 -F src/prepare.c 9ebd3a1b12bbd1951f0d6db850f32cf5d4547a6ab8bb9e958d75dfbe4e60d0a3 +F src/prepare.c eb701220a724831190d7935c8bee7f230af0c7a8f6ac13d629088f9d37a566cd F src/printf.c e99ee9741e79ae3873458146f59644276657340385ade4e76a5f5d1c25793764 F src/random.c 606b00941a1d7dd09c381d3279a058d771f406c5213c9932bbd93d5587be4b9c F src/resolve.c efea4e5fbecfd6d0a9071b0be0d952620991673391b6ffaaf4c277b0bb674633 F src/rowset.c ba9515a922af32abe1f7d39406b9d35730ed65efab9443dc5702693b60854c92 -F src/select.c 321f29e431fbb71e594cc7026391a827a0270237597d2e2401244e7602dea8bd +F src/select.c f243554e94c55dab12f812cc9043459e4299b24d326101240897bbf0090aa39a F src/shell.c.in e7fc8db64df14d1893a86dce488770efdbb1007e44ec8cd5549769533bb419f2 -F src/sqlite.h.in 1fe1836879ecbb2e28f00f44eb6092db09a2a06bf072af351c6c2466bd515496 +F src/sqlite.h.in 5e3f90b38e1865d39e55db747efe51848d9b05ba64ea21372a1abbd8367bfd8e F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8 F src/sqlite3ext.h c4b9fa7a7e2bcdf850cfeb4b8a91d5ec47b7a00033bc996fd2ee96cbf2741f5f F src/sqliteInt.h 0c9934acd88e0fa14f0d4743233b4cd7bd7bbc84099ba3cad50d8e69676ce2b9 @@ -712,13 +712,13 @@ F src/threads.c 4ae07fa022a3dc7c5beb373cf744a85d3c5c6c3c F src/tokenize.c 1305797eab3542a0896b552c6e7669c972c1468e11e92b370533c1f37a37082b F src/treeview.c 29b1dc7e0f84ba090734febe27393d4719682af0cae1b902d5ebf0236ecebea4 F src/trigger.c 5e68b790f022b8dafbfb0eb244786512a95c9575fc198719d2557d73e5795858 -F src/update.c 5b0302c47cf31b533d5dff04c497ca1d8b9d89c39727e633fbe7b882fd5ac5aa +F src/update.c 3cf1cb45674177e09338bdbe5454fb62207c7f2eb8cea288e74286467e901959 F src/upsert.c 5303dc6c518fa7d4b280ec65170f465c7a70b7ac2b22491598f6d0b4875b3145 F src/utf.c ee39565f0843775cc2c81135751ddd93eceb91a673ea2c57f61c76f288b041a0 F src/util.c 313f3154e2b85a447326f5dd15de8d31a4df6ab0c3579bd58f426ff634ec9050 F src/vacuum.c 84ce7f01f8a7a08748e107a441db83bcec13970190ddcb0c9ff522adbc1c23fd F src/vdbe.c e744259050ec9bbcd47acf9a03a66fe3305d7429c823995de11ed524ca06d16f -F src/vdbe.h 6d921884cf8ec6a53efba99f8b68e32e955367631743e29039840e781aaf547c +F src/vdbe.h c93d4bc242fc9109558aa6b3ce8acef7effe100a42c148dc63239c488ad6c060 F src/vdbeInt.h e83be1eea422758d42302941e96e59d93193c373da655a87befdc03a851e0f95 F src/vdbeapi.c 959cef4c1e5cb6589e67b3295fe9d3e45cbd109ae6618d57b74c900dbd6be0cd F src/vdbeaux.c 0b81f317c86ed9f4ba822af66a52777fed6e8180edc79d4fc62ffe75c8e52d80 @@ -2067,8 +2067,11 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0 -P dc7dd2d3e50e7cc474b22f1b5b219da32bcd7aa1ba56864d1dbcf0d3a6fa06f2 009462f2344b1f468cf9440343a47fec68d783a2bfb4fa6168bb227ec910b918 -R 6f58eb8b4613cbdc0da9cabf0de9170c -U dan -Z dd8e28132ec997579f72120c72f627ae +P 4893b4e3eafc7c9c22b24717f90a585862203f987cf108b079ce6e946093e675 +R 2462bad04e68d73a11cdd7ebb93dbee4 +T *branch * coroutines-exp1 +T *sym-coroutines-exp1 * +T -sym-trunk * +U drh +Z 3ebf6ead00c81074e10b3b13d6b1d9c7 # Remove this line to create a well-formed Fossil manifest. diff --git a/manifest.uuid b/manifest.uuid index e55b14b4b2..85de0c3c0b 100644 --- a/manifest.uuid +++ b/manifest.uuid @@ -1 +1 @@ -4893b4e3eafc7c9c22b24717f90a585862203f987cf108b079ce6e946093e675 \ No newline at end of file +e7d323c16ee774816c825b8a8e078dda8f38bbbd8d87a101a42739559196f503 \ No newline at end of file diff --git a/src/prepare.c b/src/prepare.c index 7607387408..369793f337 100644 --- a/src/prepare.c +++ b/src/prepare.c @@ -838,17 +838,32 @@ static int sqlite3LockAndPrepare( if( !sqlite3SafetyCheckOk(db)||zSql==0 ){ return SQLITE_MISUSE_BKPT; } +//prepFlags |= SQLITE_PREPARE_SAFEOPT; sqlite3_mutex_enter(db->mutex); sqlite3BtreeEnterAll(db); - do{ + while( 1 /* exit-by-break */ ){ /* Make multiple attempts to compile the SQL, until it either succeeds ** or encounters a permanent error. A schema problem after one schema ** reset is considered a permanent error. */ rc = sqlite3Prepare(db, zSql, nBytes, prepFlags, pOld, ppStmt, pzTail); assert( rc==SQLITE_OK || *ppStmt==0 ); if( rc==SQLITE_OK || db->mallocFailed ) break; - }while( (rc==SQLITE_ERROR_RETRY && (cnt++)0 ) break; + sqlite3ResetOneSchema(db,-1); + continue; + } +// if( rc==SQLITE_ERROR_UNSAFEOPT ){ +// assert( (prepFlags & SQLITE_PREPARE_SAFEOPT)==0 ); +// prepFlags |= SQLITE_PREPARE_SAFEOPT; +// continue; +// } + break; + } sqlite3BtreeLeaveAll(db); rc = sqlite3ApiExit(db, rc); assert( (rc&db->errMask)==rc ); diff --git a/src/select.c b/src/select.c index 34ba3f7a4c..0576d3489b 100644 --- a/src/select.c +++ b/src/select.c @@ -6854,6 +6854,44 @@ static int sameSrcAlias(SrcItem *p0, SrcList *pSrc){ return 0; } +/* +** Return TRUE (non-zero) if the i-th entry in the pTabList SrcList can +** be implemented as a co-routine. The i-th entry is guaranteed to be +** a subquery. +** +** The subquery is implemented as a co-routine if all of the following are +** true: +** +** (1) the subquery is the left-most subquery and there is nothing +** that would prevent it from being the outer-most loop. +** (2) the subquery is not a CTE that should be materialized +** (3) the subquery is not part of a left operand for a RIGHT JOIN +*/ +static int fromClauseTermCanBeCoroutine( + Parse *pParse, /* Parsing context */ + SrcList *pTabList, /* FROM clause */ + int i /* Which term of the FROM clause */ +){ + SrcItem *pItem = &pTabList->a[i]; + if( pItem->fg.isCte && pItem->u2.pCteUse->eM10d==M10d_Yes ) return 0; + if( pTabList->a[0].fg.jointype & JT_LTORJ ) return 0; + if( i==0 ){ + if( pTabList->nSrc==1 ) return 1; + if( pTabList->a[1].fg.jointype & JT_CROSS ) return 1; + if( pParse->prepFlags & SQLITE_PREPARE_SAFEOPT ) return 0; + return 1; + } + if( pParse->prepFlags & SQLITE_PREPARE_SAFEOPT ) return 0; + while( 1 /*exit-by-break*/ ){ + if( pItem->fg.jointype & (JT_OUTER|JT_CROSS) ) return 0; + if( i==0 ) break; + i--; + pItem--; + if( pItem->pSelect!=0 ) return 0; + } + return 1; +} + /* ** Generate code for the SELECT statement given in the p argument. ** @@ -7241,21 +7279,8 @@ int sqlite3Select( pParse->zAuthContext = pItem->zName; /* Generate code to implement the subquery - ** - ** The subquery is implemented as a co-routine if all of the following are - ** true: - ** - ** (1) the subquery is guaranteed to be the outer loop (so that - ** it does not need to be computed more than once), and - ** (2) the subquery is not a CTE that should be materialized - ** (3) the subquery is not part of a left operand for a RIGHT JOIN */ - if( i==0 - && (pTabList->nSrc==1 - || (pTabList->a[1].fg.jointype&(JT_OUTER|JT_CROSS))!=0) /* (1) */ - && (pItem->fg.isCte==0 || pItem->u2.pCteUse->eM10d!=M10d_Yes) /* (2) */ - && (pTabList->a[0].fg.jointype & JT_LTORJ)==0 /* (3) */ - ){ + if( fromClauseTermCanBeCoroutine(pParse, pTabList, i) ){ /* Implement a co-routine that will return a single row of the result ** set on each invocation. */ diff --git a/src/sqlite.h.in b/src/sqlite.h.in index 91e1e07f87..598a244937 100644 --- a/src/sqlite.h.in +++ b/src/sqlite.h.in @@ -495,6 +495,7 @@ int sqlite3_exec( #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) +#define SQLITE_ERROR_UNSAFEOPT (SQLITE_ERROR | (4<<8)) #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) diff --git a/src/update.c b/src/update.c index 809b306539..0612b2708d 100644 --- a/src/update.c +++ b/src/update.c @@ -268,6 +268,7 @@ static void updateFromSelect( if( pSelect ) pSelect->selFlags |= SF_OrderByReqd; sqlite3SelectDestInit(&dest, eDest, iEph); dest.iSDParm2 = (pPk ? pPk->nKeyCol : -1); + pParse->prepFlags |= SQLITE_PREPARE_SAFEOPT; sqlite3Select(pParse, pSelect, &dest); sqlite3SelectDelete(db, pSelect); } diff --git a/src/vdbe.h b/src/vdbe.h index a199247434..467c999343 100644 --- a/src/vdbe.h +++ b/src/vdbe.h @@ -165,6 +165,7 @@ typedef struct VdbeOpList VdbeOpList; ** Additional non-public SQLITE_PREPARE_* flags */ #define SQLITE_PREPARE_SAVESQL 0x80 /* Preserve SQL text */ +#define SQLITE_PREPARE_SAFEOPT 0x40 /* Use only safe optimizations */ #define SQLITE_PREPARE_MASK 0x0f /* Mask of public flags */ /* -- 2.39.5