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Overview
| Comment: | Fix a problem with eponymous virtual tables and SHARED_SCHEMA databases. Also, after preparing statements that require all database schemas (REINDEX, ANALYZE, CREATE, DROP and some PRAGMA statements), do not allow the database connection to return more than one schema to each schema-pool. |
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| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | reuse-schema |
| Files: | files | file ages | folders |
| SHA3-256: | ecf6251ec0bb745a4ef9bad9f9ecd3ba |
| User & Date: | dan 2019-02-15 19:00:41 |
| Wiki: | reuse-schema |
Context
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2019-02-15
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| 19:36 | Enhance the virtual table in test_schemapool.c so that it can be used to check that SHARED_SCHEMA connections are not allocating and freeing schemas when they should not be. check-in: cb236cb9 user: dan tags: reuse-schema | |
| 19:00 | Fix a problem with eponymous virtual tables and SHARED_SCHEMA databases. Also, after preparing statements that require all database schemas (REINDEX, ANALYZE, CREATE, DROP and some PRAGMA statements), do not allow the database connection to return more than one schema to each schema-pool. check-in: ecf6251e user: dan tags: reuse-schema | |
| 11:54 | Revert the rearrangement of VDBE code in [219b39e14] so that vdbe.c matches trunk. Since the new call to sqlite3Init() in OP_ParseSchema was removed, the rearrangement no longer provides any performance advantage. check-in: 03c4f003 user: dan tags: reuse-schema | |
Changes
Changes to src/attach.c.
228 228 /* If the file was opened successfully, read the schema for the new database. 229 229 ** If this fails, or if opening the file failed, then close the file and 230 230 ** remove the entry from the db->aDb[] array. i.e. put everything back the 231 231 ** way we found it. 232 232 */ 233 233 if( rc==SQLITE_OK ){ 234 234 db->init.iDb = 0; 235 - db->mDbFlags &= ~(DBFLAG_SchemaKnownOk); 236 235 if( !IsReuseSchema(db) ){ 236 + db->mDbFlags &= ~(DBFLAG_SchemaKnownOk); 237 237 sqlite3BtreeEnterAll(db); 238 238 rc = sqlite3Init(db, &zErrDyn); 239 239 sqlite3BtreeLeaveAll(db); 240 240 assert( zErrDyn==0 || rc!=SQLITE_OK ); 241 241 } 242 242 } 243 243 #ifdef SQLITE_USER_AUTHENTICATION
Changes to src/build.c.
396 396 Module *pMod = (Module*)sqlite3HashFind(&db->aModule, zName); 397 397 if( pMod==0 && sqlite3_strnicmp(zName, "pragma_", 7)==0 ){ 398 398 pMod = sqlite3PragmaVtabRegister(db, zName); 399 399 } 400 400 if( pMod ){ 401 401 sqlite3SchemaLoad(db, 0); 402 402 if( sqlite3VtabEponymousTableInit(pParse, pMod) ){ 403 - return pMod->pEpoTab; 403 + Table *pEpoTab = pMod->pEpoTab; 404 + assert( IsReuseSchema(db) || pEpoTab->pSchema==db->aDb[0].pSchema ); 405 + pEpoTab->pSchema = db->aDb[0].pSchema; /* For SHARED_SCHEMA mode */ 406 + return pEpoTab; 404 407 } 405 408 } 406 409 } 407 410 #endif 408 411 if( flags & LOCATE_NOERR ) return 0; 409 412 pParse->checkSchema = 1; 410 413 }else if( IsVirtual(p) && pParse->disableVtab ){
Changes to src/callback.c.
599 599 ** When this function is called, the database connection Db must be 600 600 ** using a schema-pool (Db.pSPool!=0) and must currently have Db.pSchema 601 601 ** set to point to a populated schema object checked out from the 602 602 ** schema-pool. It is also assumed that the STATIC_MASTER mutex is held. 603 603 ** This function returns the Schema object to the schema-pool and sets 604 604 ** Db.pSchema to point to the schema-pool's static, empty, Schema object. 605 605 */ 606 -static void schemaRelease(Db *pDb){ 607 - assert( pDb->pSPool && pDb->pSchema ); 608 - assert( pDb->pSchema->schemaFlags & DB_SchemaLoaded ); 606 +static void schemaRelease(sqlite3 *db, Db *pDb){ 607 + Schema *pRelease = pDb->pSchema; 608 + SchemaPool *pSPool = pDb->pSPool; 609 + 610 + pDb->pSchema = &pSPool->sSchema; 611 + 612 + assert( pDb->pSPool && pRelease ); 613 + assert( pRelease->schemaFlags & DB_SchemaLoaded ); 614 + assert( (pDb->pSchema->schemaFlags & DB_SchemaLoaded)==0 ); 609 615 assert( sqlite3_mutex_held(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER)) ); 610 616 611 - pDb->pSchema->pNext = pDb->pSPool->pSchema; 612 - pDb->pSPool->pSchema = pDb->pSchema; 613 - pDb->pSchema = &pDb->pSPool->sSchema; 617 + /* If the DBFLAG_FreeSchema flag is set and the database connection holds 618 + ** at least one other copy of the schema being released, delete it instead 619 + ** of returning it to the schema-pool. */ 620 + if( db->mDbFlags & DBFLAG_FreeSchema ){ 621 + int i; 622 + for(i=0; i<db->nDb; i++){ 623 + Db *p = &db->aDb[i]; 624 + if( p!=pDb && p->pSchema!=&pSPool->sSchema && pDb->pSPool==p->pSPool ){ 625 + schemaDelete(pRelease); 626 + return; 627 + } 628 + } 629 + } 614 630 615 - assert( (pDb->pSchema->schemaFlags & DB_SchemaLoaded)==0 ); 631 + pRelease->pNext = pDb->pSPool->pSchema; 632 + pDb->pSPool->pSchema = pRelease; 616 633 } 617 634 618 635 /* 619 636 ** The schema for database iDb of database handle db, which was opened 620 637 ** with SQLITE_OPEN_SHARED_SCHEMA, has just been parsed. This function either 621 638 ** finds a matching SchemaPool object on the global list (schemaPoolList) or 622 639 ** else allocates a new one and sets the Db.pSPool variable accordingly. ................................................................................ 706 723 for(p=pDb->pVTable; p; p=pNext){ 707 724 pNext = p->pNext; 708 725 sqlite3VtabUnlock(p); 709 726 } 710 727 pDb->pVTable = 0; 711 728 sqlite3_mutex_enter( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) ); 712 729 if( DbHasProperty(db, iDb, DB_SchemaLoaded) ){ 713 - schemaRelease(pDb); 730 + schemaRelease(db, pDb); 714 731 } 715 732 if( bNew ){ 716 733 Schema *pNew = sqlite3SchemaGet(db, 0); 717 734 if( pNew==0 ){ 718 735 rc = SQLITE_NOMEM; 719 736 }else{ 720 737 pDb->pSchema = pNew; ................................................................................ 770 787 int i; 771 788 assert_schema_state_ok(db); 772 789 sqlite3_mutex_enter( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) ); 773 790 for(i=0; i<db->nDb; i++){ 774 791 if( i!=1 ){ 775 792 Db *pDb = &db->aDb[i]; 776 793 if( pDb->pSPool && DbHasProperty(db,i,DB_SchemaLoaded) ){ 777 - schemaRelease(pDb); 794 + schemaRelease(db, pDb); 778 795 } 779 796 } 780 797 } 798 + db->flags &= ~DBFLAG_FreeSchema; 781 799 sqlite3_mutex_leave( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) ); 782 800 } 783 801 784 802 /* 785 803 ** Release any sharable schema held by connection iDb of database handle 786 804 ** db. Db.pSchema is left pointing to the static, empty, Schema object 787 805 ** owned by the schema-pool. ................................................................................ 788 806 */ 789 807 void sqlite3SchemaRelease(sqlite3 *db, int iDb){ 790 808 Db *pDb = &db->aDb[iDb]; 791 809 assert( iDb!=1 ); 792 810 assert_schema_state_ok(db); 793 811 sqlite3_mutex_enter( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) ); 794 812 if( pDb->pSPool && DbHasProperty(db, iDb, DB_SchemaLoaded) ){ 795 - schemaRelease(pDb); 813 + schemaRelease(db, pDb); 796 814 } 797 815 sqlite3_mutex_leave( sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER) ); 798 816 } 799 817 800 818 /* 801 819 ** In most cases, this function finds and returns the schema associated 802 820 ** with BTree handle pBt, creating a new one if necessary. However, if
Changes to src/prepare.c.
477 477 ** Otherwise, the schema is loaded. An error code is returned. 478 478 */ 479 479 int sqlite3ReadSchema(Parse *pParse){ 480 480 int rc = SQLITE_OK; 481 481 sqlite3 *db = pParse->db; 482 482 assert( sqlite3_mutex_held(db->mutex) ); 483 483 if( !db->init.busy ){ 484 + db->mDbFlags |= DBFLAG_FreeSchema; /* For sharable-schema mode */ 484 485 rc = sqlite3Init(db, &pParse->zErrMsg); 485 486 if( rc!=SQLITE_OK ){ 486 487 pParse->rc = rc; 487 488 pParse->nErr++; 488 489 }else if( db->noSharedCache && !IsReuseSchema(db) ){ 489 490 db->mDbFlags |= DBFLAG_SchemaKnownOk; 490 491 }
Changes to src/sqliteInt.h.
1569 1569 ** Allowed values for sqlite3.mDbFlags 1570 1570 */ 1571 1571 #define DBFLAG_SchemaChange 0x0001 /* Uncommitted Hash table changes */ 1572 1572 #define DBFLAG_PreferBuiltin 0x0002 /* Preference to built-in funcs */ 1573 1573 #define DBFLAG_Vacuum 0x0004 /* Currently in a VACUUM */ 1574 1574 #define DBFLAG_SchemaKnownOk 0x0008 /* Schema is known to be valid */ 1575 1575 1576 -#define DBFLAG_SchemaInuse 0x0010 /* Do not free schemas */ 1576 +#define DBFLAG_SchemaInuse 0x0010 /* Do not release sharable schemas */ 1577 +#define DBFLAG_FreeSchema 0x0020 /* Free extra shared schemas on release */ 1577 1578 1578 1579 /* 1579 1580 ** Bits of the sqlite3.dbOptFlags field that are used by the 1580 1581 ** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface to 1581 1582 ** selectively disable various optimizations. 1582 1583 */ 1583 1584 #define SQLITE_QueryFlattener 0x0001 /* Query flattening */
Changes to test/reuse2.test.
294 294 sqlite3_table_column_metadata db2 main bbb b 295 295 } {{} BINARY 0 0 0} 296 296 297 297 do_execsql_test -db db2 5.2.3 { 298 298 SELECT 'nref=' || nRef, 'nschema=' || nSchema FROM schemapool ORDER BY 1; 299 299 } {nref=6 nschema=1} 300 300 301 +breakpoint 302 +do_execsql_test -db db2 5.2.4 { 303 + PRAGMA integrity_check; 304 + SELECT 'nref=' || nRef, 'nschema=' || nSchema FROM schemapool ORDER BY 1; 305 +} {ok nref=6 nschema=1} 306 + 301 307 finish_test 302 308
Changes to test/reuse3.test.
105 105 set N [lindex [sqlite3_db_status db1 SCHEMA_USED 0] 1] 106 106 expr $N==$N 107 107 } 1 108 108 109 109 sqlite3 db2 test.db -shared-schema 1 110 110 do_test 3.2 { 111 111 execsql { SELECT * FROM x1 } db2 112 - breakpoint 113 112 set N2 [lindex [sqlite3_db_status db2 SCHEMA_USED 0] 1] 114 113 expr $N2>($N/2) && $N2<($N/2)+400 115 114 } 1 116 115 117 116 sqlite3 db3 test.db -shared-schema 1 118 117 sqlite3 db4 test.db -shared-schema 1 119 118 do_test 3.3 { ................................................................................ 120 119 execsql { SELECT * FROM x1 } db3 121 120 execsql { SELECT * FROM x1 } db4 122 121 set N4 [lindex [sqlite3_db_status db2 SCHEMA_USED 0] 1] 123 122 set M [expr 2*($N-$N2)] 124 123 expr {$N4 == (($M / 4) + $N-$M)} 125 124 } 1 126 125 126 +catch { db1 close } 127 +catch { db2 close } 128 +catch { db3 close } 129 +catch { db4 close } 130 + 131 +#------------------------------------------------------------------------- 132 +# Test the REINDEX command. 133 +reset_db 134 +do_execsql_test 4.1.0 { 135 + CREATE TABLE x1(a, b, c); 136 + CREATE INDEX x1a ON x1(a); 137 + CREATE INDEX x1b ON x1(b); 138 + CREATE INDEX x1c ON x1(c); 139 +} 140 +db close 141 +sqlite3 db test.db -shared-schema 1 142 + 143 +do_execsql_test 4.1.1 { 144 + REINDEX x1; 145 + REINDEX x1a; 146 + REINDEX x1b; 147 + REINDEX x1c; 148 + REINDEX; 149 +} 150 + 151 +do_test 4.1.2 { 152 + for {set i 1} {$i < 5} {incr i} { 153 + forcedelete test.db${i} test.db${i}-wal test.db${i}-journal 154 + forcecopy test.db test.db${i} 155 + execsql "ATTACH 'test.db${i}' AS db${i}" 156 + } 157 + register_schemapool_module db 158 + set {} {} 159 + execsql { SELECT 'nref=' || nRef, 'nschema=' || nSchema FROM schemapool } 160 +} {nref=5 nschema=1} 161 + 162 +do_execsql_test 4.1.3 { 163 + REINDEX x1; 164 + REINDEX x1a; 165 + REINDEX x1b; 166 + REINDEX x1c; 167 + REINDEX db1.x1a; 168 + REINDEX db2.x1b; 169 + REINDEX db3.x1c; 170 + REINDEX; 171 +} 172 + 173 +do_execsql_test 4.1.4 { 174 + SELECT 'nref=' || nRef, 'nschema=' || nSchema FROM schemapool; 175 +} {nref=5 nschema=1} 176 + 127 177 finish_test 128 178