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Overview
Comment: | Avoid unnecessary memset() calls in the query optimizer. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
5bb7cde0731d23411e9df02a957010f9 |
User & Date: | drh 2016-10-03 14:44:47.342 |
Context
2016-10-03
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15:28 | Avoid unnecessary strlen() calls in sqlite3ExprAssignVarNumber() by passing in the token length from the parser. (check-in: d15ae2e530 user: drh tags: trunk) | |
14:44 | Avoid unnecessary memset() calls in the query optimizer. (check-in: 5bb7cde073 user: drh tags: trunk) | |
12:56 | Fix an obsolete comment on a variable definition in expr.c. No code changes. (check-in: 012ff6dd30 user: drh tags: trunk) | |
Changes
Changes to src/where.c.
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4403 4404 4405 4406 4407 4408 4409 | ** return value. A single allocation is used to store the WhereInfo ** struct, the contents of WhereInfo.a[], the WhereClause structure ** and the WhereMaskSet structure. Since WhereClause contains an 8-byte ** field (type Bitmask) it must be aligned on an 8-byte boundary on ** some architectures. Hence the ROUND8() below. */ nByteWInfo = ROUND8(sizeof(WhereInfo)+(nTabList-1)*sizeof(WhereLevel)); | | < < > > > > > | 4403 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 | ** return value. A single allocation is used to store the WhereInfo ** struct, the contents of WhereInfo.a[], the WhereClause structure ** and the WhereMaskSet structure. Since WhereClause contains an 8-byte ** field (type Bitmask) it must be aligned on an 8-byte boundary on ** some architectures. Hence the ROUND8() below. */ nByteWInfo = ROUND8(sizeof(WhereInfo)+(nTabList-1)*sizeof(WhereLevel)); pWInfo = sqlite3DbMallocRawNN(db, nByteWInfo + sizeof(WhereLoop)); if( db->mallocFailed ){ sqlite3DbFree(db, pWInfo); pWInfo = 0; goto whereBeginError; } pWInfo->pParse = pParse; pWInfo->pTabList = pTabList; pWInfo->pOrderBy = pOrderBy; pWInfo->pDistinctSet = pDistinctSet; pWInfo->aiCurOnePass[0] = pWInfo->aiCurOnePass[1] = -1; pWInfo->nLevel = nTabList; pWInfo->iBreak = pWInfo->iContinue = sqlite3VdbeMakeLabel(v); pWInfo->wctrlFlags = wctrlFlags; pWInfo->iLimit = iAuxArg; pWInfo->savedNQueryLoop = pParse->nQueryLoop; memset(&pWInfo->nOBSat, 0, offsetof(WhereInfo,sWC) - offsetof(WhereInfo,nOBSat)); memset(&pWInfo->a[0], 0, sizeof(WhereLoop)+nTabList*sizeof(WhereLevel)); assert( pWInfo->eOnePass==ONEPASS_OFF ); /* ONEPASS defaults to OFF */ pMaskSet = &pWInfo->sMaskSet; sWLB.pWInfo = pWInfo; sWLB.pWC = &pWInfo->sWC; sWLB.pNew = (WhereLoop*)(((char*)pWInfo)+nByteWInfo); assert( EIGHT_BYTE_ALIGNMENT(sWLB.pNew) ); whereLoopInit(sWLB.pNew); |
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Changes to src/whereInt.h.
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242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 | ** ** The number of terms in a join is limited by the number of bits ** in prereqRight and prereqAll. The default is 64 bits, hence SQLite ** is only able to process joins with 64 or fewer tables. */ struct WhereTerm { Expr *pExpr; /* Pointer to the subexpression that is this term */ int iParent; /* Disable pWC->a[iParent] when this term disabled */ int leftCursor; /* Cursor number of X in "X <op> <expr>" */ int iField; /* Field in (?,?,?) IN (SELECT...) vector */ union { int leftColumn; /* Column number of X in "X <op> <expr>" */ WhereOrInfo *pOrInfo; /* Extra information if (eOperator & WO_OR)!=0 */ WhereAndInfo *pAndInfo; /* Extra information if (eOperator& WO_AND)!=0 */ } u; | > > > > > > < < < < < < | 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 | ** ** The number of terms in a join is limited by the number of bits ** in prereqRight and prereqAll. The default is 64 bits, hence SQLite ** is only able to process joins with 64 or fewer tables. */ struct WhereTerm { Expr *pExpr; /* Pointer to the subexpression that is this term */ WhereClause *pWC; /* The clause this term is part of */ LogEst truthProb; /* Probability of truth for this expression */ u16 wtFlags; /* TERM_xxx bit flags. See below */ u16 eOperator; /* A WO_xx value describing <op> */ u8 nChild; /* Number of children that must disable us */ u8 eMatchOp; /* Op for vtab MATCH/LIKE/GLOB/REGEXP terms */ int iParent; /* Disable pWC->a[iParent] when this term disabled */ int leftCursor; /* Cursor number of X in "X <op> <expr>" */ int iField; /* Field in (?,?,?) IN (SELECT...) vector */ union { int leftColumn; /* Column number of X in "X <op> <expr>" */ WhereOrInfo *pOrInfo; /* Extra information if (eOperator & WO_OR)!=0 */ WhereAndInfo *pAndInfo; /* Extra information if (eOperator& WO_AND)!=0 */ } u; Bitmask prereqRight; /* Bitmask of tables used by pExpr->pRight */ Bitmask prereqAll; /* Bitmask of tables referenced by pExpr */ }; /* ** Allowed values of WhereTerm.wtFlags */ |
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408 409 410 411 412 413 414 | ** planner. */ struct WhereInfo { Parse *pParse; /* Parsing and code generating context */ SrcList *pTabList; /* List of tables in the join */ ExprList *pOrderBy; /* The ORDER BY clause or NULL */ ExprList *pDistinctSet; /* DISTINCT over all these values */ | < < < > > > > > < | | | | < | 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 | ** planner. */ struct WhereInfo { Parse *pParse; /* Parsing and code generating context */ SrcList *pTabList; /* List of tables in the join */ ExprList *pOrderBy; /* The ORDER BY clause or NULL */ ExprList *pDistinctSet; /* DISTINCT over all these values */ LogEst iLimit; /* LIMIT if wctrlFlags has WHERE_USE_LIMIT */ int aiCurOnePass[2]; /* OP_OpenWrite cursors for the ONEPASS opt */ int iContinue; /* Jump here to continue with next record */ int iBreak; /* Jump here to break out of the loop */ int savedNQueryLoop; /* pParse->nQueryLoop outside the WHERE loop */ u16 wctrlFlags; /* Flags originally passed to sqlite3WhereBegin() */ u8 nLevel; /* Number of nested loop */ i8 nOBSat; /* Number of ORDER BY terms satisfied by indices */ u8 sorted; /* True if really sorted (not just grouped) */ u8 eOnePass; /* ONEPASS_OFF, or _SINGLE, or _MULTI */ u8 untestedTerms; /* Not all WHERE terms resolved by outer loop */ u8 eDistinct; /* One of the WHERE_DISTINCT_* values */ u8 bOrderedInnerLoop; /* True if only the inner-most loop is ordered */ int iTop; /* The very beginning of the WHERE loop */ WhereLoop *pLoops; /* List of all WhereLoop objects */ Bitmask revMask; /* Mask of ORDER BY terms that need reversing */ LogEst nRowOut; /* Estimated number of output rows */ WhereClause sWC; /* Decomposition of the WHERE clause */ WhereMaskSet sMaskSet; /* Map cursor numbers to bitmasks */ WhereLevel a[1]; /* Information about each nest loop in WHERE */ }; /* ** Private interfaces - callable only by other where.c routines. ** ** where.c: |
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Changes to src/whereexpr.c.
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73 74 75 76 77 78 79 | return 0; } memcpy(pWC->a, pOld, sizeof(pWC->a[0])*pWC->nTerm); if( pOld!=pWC->aStatic ){ sqlite3DbFree(db, pOld); } pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]); | < > > | 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 | return 0; } memcpy(pWC->a, pOld, sizeof(pWC->a[0])*pWC->nTerm); if( pOld!=pWC->aStatic ){ sqlite3DbFree(db, pOld); } pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]); } pTerm = &pWC->a[idx = pWC->nTerm++]; if( p && ExprHasProperty(p, EP_Unlikely) ){ pTerm->truthProb = sqlite3LogEst(p->iTable) - 270; }else{ pTerm->truthProb = 1; } pTerm->pExpr = sqlite3ExprSkipCollate(p); pTerm->wtFlags = wtFlags; pTerm->pWC = pWC; pTerm->iParent = -1; memset(&pTerm->eOperator, 0, sizeof(WhereTerm) - offsetof(WhereTerm,eOperator)); return idx; } /* ** Return TRUE if the given operator is one of the operators that is ** allowed for an indexable WHERE clause term. The allowed operators are ** "=", "<", ">", "<=", ">=", "IN", "IS", and "IS NULL" |
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