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Overview
Comment: | Enhance the use of the column cache for UPDATE statements, making them more efficient for the case where a column is modified to be an expression of other unmodified columns. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
871e091df651b2275a672c35ff938bd4 |
User & Date: | drh 2015-10-15 19:21:51.254 |
References
2018-04-26
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12:45 | • New ticket [d85fffd6ff] VDBE program uses an expired value. (artifact: 4af4529426 user: drh) | |
Context
2015-10-15
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21:30 | Performance optimization for the OP_Column opcode. (check-in: 076be5474d user: drh tags: trunk) | |
21:13 | Merge updates from trunk. (Leaf check-in: 4049368008 user: mistachkin tags: mutexInitIsInitReCheck) | |
21:12 | Merge updates from trunk. (Leaf check-in: a447cf90dd user: mistachkin tags: mutexInitSimpleCmpSwap) | |
20:17 | Experiments with an OP_Unpack opcode that extracts multiple columns from a record without caching. (Leaf check-in: 39ae92f5c6 user: drh tags: unpack-opcode) | |
19:21 | Enhance the use of the column cache for UPDATE statements, making them more efficient for the case where a column is modified to be an expression of other unmodified columns. (check-in: 871e091df6 user: drh tags: trunk) | |
18:04 | Add the OP_IntCopy opcode - an optimized version of OP_SCopy that only works for integer values. (check-in: 3a2f73a492 user: drh tags: trunk) | |
Changes
Changes to src/expr.c.
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2477 2478 2479 2480 2481 2482 2483 | if( iCol>=0 ){ sqlite3ColumnDefault(v, pTab, iCol, regOut); } } /* ** Generate code that will extract the iColumn-th column from | | > | | > > | | 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 | if( iCol>=0 ){ sqlite3ColumnDefault(v, pTab, iCol, regOut); } } /* ** Generate code that will extract the iColumn-th column from ** table pTab and store the column value in a register. ** ** An effort is made to store the column value in register iReg. This ** is not garanteeed for GetColumn() - the result can be stored in ** any register. But the result is guaranteed to land in register iReg ** for GetColumnToReg(). ** ** There must be an open cursor to pTab in iTable when this routine ** is called. If iColumn<0 then code is generated that extracts the rowid. */ int sqlite3ExprCodeGetColumn( Parse *pParse, /* Parsing and code generating context */ Table *pTab, /* Description of the table we are reading from */ int iColumn, /* Index of the table column */ int iTable, /* The cursor pointing to the table */ int iReg, /* Store results here */ u8 p5 /* P5 value for OP_Column + FLAGS */ ){ Vdbe *v = pParse->pVdbe; int i; struct yColCache *p; for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){ if( p->iReg>0 && p->iTable==iTable && p->iColumn==iColumn ){ |
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2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 | if( p5 ){ sqlite3VdbeChangeP5(v, p5); }else{ sqlite3ExprCacheStore(pParse, iTable, iColumn, iReg); } return iReg; } /* ** Clear all column cache entries. */ void sqlite3ExprCacheClear(Parse *pParse){ int i; struct yColCache *p; | > > > > > > > > > > > | 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 | if( p5 ){ sqlite3VdbeChangeP5(v, p5); }else{ sqlite3ExprCacheStore(pParse, iTable, iColumn, iReg); } return iReg; } void sqlite3ExprCodeGetColumnToReg( Parse *pParse, /* Parsing and code generating context */ Table *pTab, /* Description of the table we are reading from */ int iColumn, /* Index of the table column */ int iTable, /* The cursor pointing to the table */ int iReg /* Store results here */ ){ int r1 = sqlite3ExprCodeGetColumn(pParse, pTab, iColumn, iTable, iReg, 0); if( r1!=iReg ) sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, r1, iReg); } /* ** Clear all column cache entries. */ void sqlite3ExprCacheClear(Parse *pParse){ int i; struct yColCache *p; |
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Changes to src/select.c.
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5291 5292 5293 5294 5295 5296 5297 | sqlite3ExprCacheClear(pParse); sqlite3ExprCodeExprList(pParse, pGroupBy, regBase, 0, 0); j = nGroupBy; for(i=0; i<sAggInfo.nColumn; i++){ struct AggInfo_col *pCol = &sAggInfo.aCol[i]; if( pCol->iSorterColumn>=j ){ int r1 = j + regBase; | < < | | < < < | 5291 5292 5293 5294 5295 5296 5297 5298 5299 5300 5301 5302 5303 5304 5305 5306 | sqlite3ExprCacheClear(pParse); sqlite3ExprCodeExprList(pParse, pGroupBy, regBase, 0, 0); j = nGroupBy; for(i=0; i<sAggInfo.nColumn; i++){ struct AggInfo_col *pCol = &sAggInfo.aCol[i]; if( pCol->iSorterColumn>=j ){ int r1 = j + regBase; sqlite3ExprCodeGetColumnToReg(pParse, pCol->pTab, pCol->iColumn, pCol->iTable, r1); j++; } } regRecord = sqlite3GetTempReg(pParse); sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regRecord); sqlite3VdbeAddOp2(v, OP_SorterInsert, sAggInfo.sortingIdx, regRecord); sqlite3ReleaseTempReg(pParse, regRecord); |
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Changes to src/sqliteInt.h.
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3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 | int sqlite3WhereBreakLabel(WhereInfo*); int sqlite3WhereOkOnePass(WhereInfo*, int*); #define ONEPASS_OFF 0 /* Use of ONEPASS not allowed */ #define ONEPASS_SINGLE 1 /* ONEPASS valid for a single row update */ #define ONEPASS_MULTI 2 /* ONEPASS is valid for multiple rows */ void sqlite3ExprCodeLoadIndexColumn(Parse*, Index*, int, int, int); int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8); void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int); void sqlite3ExprCodeMove(Parse*, int, int, int); void sqlite3ExprCacheStore(Parse*, int, int, int); void sqlite3ExprCachePush(Parse*); void sqlite3ExprCachePop(Parse*); void sqlite3ExprCacheRemove(Parse*, int, int); void sqlite3ExprCacheClear(Parse*); | > | 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 | int sqlite3WhereBreakLabel(WhereInfo*); int sqlite3WhereOkOnePass(WhereInfo*, int*); #define ONEPASS_OFF 0 /* Use of ONEPASS not allowed */ #define ONEPASS_SINGLE 1 /* ONEPASS valid for a single row update */ #define ONEPASS_MULTI 2 /* ONEPASS is valid for multiple rows */ void sqlite3ExprCodeLoadIndexColumn(Parse*, Index*, int, int, int); int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8); void sqlite3ExprCodeGetColumnToReg(Parse*, Table*, int, int, int); void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int); void sqlite3ExprCodeMove(Parse*, int, int, int); void sqlite3ExprCacheStore(Parse*, int, int, int); void sqlite3ExprCachePush(Parse*); void sqlite3ExprCachePop(Parse*); void sqlite3ExprCacheRemove(Parse*, int, int); void sqlite3ExprCacheClear(Parse*); |
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Changes to src/update.c.
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518 519 520 521 522 523 524 | /* This branch loads the value of a column that will not be changed ** into a register. This is done if there are no BEFORE triggers, or ** if there are one or more BEFORE triggers that use this value via ** a new.* reference in a trigger program. */ testcase( i==31 ); testcase( i==32 ); | | | 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 | /* This branch loads the value of a column that will not be changed ** into a register. This is done if there are no BEFORE triggers, or ** if there are one or more BEFORE triggers that use this value via ** a new.* reference in a trigger program. */ testcase( i==31 ); testcase( i==32 ); sqlite3ExprCodeGetColumnToReg(pParse, pTab, i, iDataCur, regNew+i); }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i); } } } /* Fire any BEFORE UPDATE triggers. This happens before constraints are |
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Changes to src/wherecode.c.
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1301 1302 1303 1304 1305 1306 1307 | int nPk = pPk->nKeyCol; int iPk; /* Read the PK into an array of temp registers. */ r = sqlite3GetTempRange(pParse, nPk); for(iPk=0; iPk<nPk; iPk++){ int iCol = pPk->aiColumn[iPk]; | < | < < < | 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 | int nPk = pPk->nKeyCol; int iPk; /* Read the PK into an array of temp registers. */ r = sqlite3GetTempRange(pParse, nPk); for(iPk=0; iPk<nPk; iPk++){ int iCol = pPk->aiColumn[iPk]; sqlite3ExprCodeGetColumnToReg(pParse, pTab, iCol, iCur, r+iPk); } /* Check if the temp table already contains this key. If so, ** the row has already been included in the result set and ** can be ignored (by jumping past the Gosub below). Otherwise, ** insert the key into the temp table and proceed with processing ** the row. |
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