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Overview
| Comment: | Factor some work out of the index loop of the bestBtreeIndex() routine for a small performance increase. |
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| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
92c9ab56b1c67b9468bec57ab1d2c483 |
| User & Date: | drh 2012-12-08 22:14:29 |
Context
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2012-12-10
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| 09:08 | Remove a reference to JumpOnce from a comment in vdbe.c. No code changes. (check-in: ee662c03 user: dan tags: trunk) | |
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2012-12-08
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| 23:37 | Pull the latest trunk changes into the sessions branch, and in particular the collating-sequence refactorization. (check-in: 4f6d69ae user: drh tags: sessions) | |
| 22:14 | Factor some work out of the index loop of the bestBtreeIndex() routine for a small performance increase. (check-in: 92c9ab56 user: drh tags: trunk) | |
| 21:51 | Refactor collating-sequence handling as a fix for ticket [71e333e7d2e642]. The Expr.pColl field is removed from the Expr object. The COLLATE operator now becomes a separate instance of Expr in the expression tree. The code generator looks up the correct collating function as needed, rather than referring to Expr.pColl. (check-in: 8542e618 user: drh tags: trunk) | |
Changes
Changes to src/where.c.
3028 3028 Index *pIdx; /* Copy of pProbe, or zero for IPK index */ 3029 3029 int eqTermMask; /* Current mask of valid equality operators */ 3030 3030 int idxEqTermMask; /* Index mask of valid equality operators */ 3031 3031 Index sPk; /* A fake index object for the primary key */ 3032 3032 tRowcnt aiRowEstPk[2]; /* The aiRowEst[] value for the sPk index */ 3033 3033 int aiColumnPk = -1; /* The aColumn[] value for the sPk index */ 3034 3034 int wsFlagMask; /* Allowed flags in p->cost.plan.wsFlag */ 3035 + int nPriorSat; /* ORDER BY terms satisfied by outer loops */ 3036 + int nOrderBy; /* Number of ORDER BY terms */ 3037 + char bSortInit; /* Initializer for bSort in inner loop */ 3038 + char bDistInit; /* Initializer for bDist in inner loop */ 3039 + 3035 3040 3036 3041 /* Initialize the cost to a worst-case value */ 3037 3042 memset(&p->cost, 0, sizeof(p->cost)); 3038 3043 p->cost.rCost = SQLITE_BIG_DBL; 3039 3044 3040 3045 /* If the pSrc table is the right table of a LEFT JOIN then we may not 3041 3046 ** use an index to satisfy IS NULL constraints on that table. This is ................................................................................ 3076 3081 pProbe = &sPk; 3077 3082 wsFlagMask = ~( 3078 3083 WHERE_COLUMN_IN|WHERE_COLUMN_EQ|WHERE_COLUMN_NULL|WHERE_COLUMN_RANGE 3079 3084 ); 3080 3085 eqTermMask = WO_EQ|WO_IN; 3081 3086 pIdx = 0; 3082 3087 } 3088 + 3089 + nOrderBy = p->pOrderBy ? p->pOrderBy->nExpr : 0; 3090 + if( p->i ){ 3091 + nPriorSat = p->aLevel[p->i-1].plan.nOBSat; 3092 + bSortInit = nPriorSat<nOrderBy; 3093 + bDistInit = 0; 3094 + }else{ 3095 + nPriorSat = 0; 3096 + bSortInit = nOrderBy>0; 3097 + bDistInit = p->pDistinct!=0; 3098 + } 3083 3099 3084 3100 /* Loop over all indices looking for the best one to use 3085 3101 */ 3086 3102 for(; pProbe; pIdx=pProbe=pProbe->pNext){ 3087 3103 const tRowcnt * const aiRowEst = pProbe->aiRowEst; 3088 3104 WhereCost pc; /* Cost of using pProbe */ 3089 3105 double log10N = (double)1; /* base-10 logarithm of nRow (inexact) */ ................................................................................ 3154 3170 ** SELECT a, b FROM tbl WHERE a = 1; 3155 3171 ** SELECT a, b, c FROM tbl WHERE a = 1; 3156 3172 */ 3157 3173 int bInEst = 0; /* True if "x IN (SELECT...)" seen */ 3158 3174 int nInMul = 1; /* Number of distinct equalities to lookup */ 3159 3175 double rangeDiv = (double)1; /* Estimated reduction in search space */ 3160 3176 int nBound = 0; /* Number of range constraints seen */ 3161 - int bSort; /* True if external sort required */ 3162 - int bDist; /* True if index cannot help with DISTINCT */ 3163 - int bLookup = 0; /* True if not a covering index */ 3164 - int nPriorSat; /* ORDER BY terms satisfied by outer loops */ 3165 - int nOrderBy; /* Number of ORDER BY terms */ 3177 + char bSort = bSortInit; /* True if external sort required */ 3178 + char bDist = bDistInit; /* True if index cannot help with DISTINCT */ 3179 + char bLookup = 0; /* True if not a covering index */ 3166 3180 WhereTerm *pTerm; /* A single term of the WHERE clause */ 3167 3181 #ifdef SQLITE_ENABLE_STAT3 3168 3182 WhereTerm *pFirstTerm = 0; /* First term matching the index */ 3169 3183 #endif 3170 3184 3171 3185 WHERETRACE(( 3172 3186 " %s(%s):\n", 3173 3187 pSrc->pTab->zName, (pIdx ? pIdx->zName : "ipk") 3174 3188 )); 3175 3189 memset(&pc, 0, sizeof(pc)); 3176 - nOrderBy = p->pOrderBy ? p->pOrderBy->nExpr : 0; 3177 - if( p->i ){ 3178 - nPriorSat = pc.plan.nOBSat = p->aLevel[p->i-1].plan.nOBSat; 3179 - bSort = nPriorSat<nOrderBy; 3180 - bDist = 0; 3181 - }else{ 3182 - nPriorSat = pc.plan.nOBSat = 0; 3183 - bSort = nOrderBy>0; 3184 - bDist = p->pDistinct!=0; 3185 - } 3190 + pc.plan.nOBSat = nPriorSat; 3186 3191 3187 3192 /* Determine the values of pc.plan.nEq and nInMul */ 3188 3193 for(pc.plan.nEq=0; pc.plan.nEq<pProbe->nColumn; pc.plan.nEq++){ 3189 3194 int j = pProbe->aiColumn[pc.plan.nEq]; 3190 3195 pTerm = findTerm(pWC, iCur, j, p->notReady, eqTermMask, pIdx); 3191 3196 if( pTerm==0 ) break; 3192 3197 pc.plan.wsFlags |= (WHERE_COLUMN_EQ|WHERE_ROWID_EQ);