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Overview
| Comment: | Avoid trying to allocation zero bytes when analyzing a unique non-null index. |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | faster-analyze |
| Files: | files | file ages | folders |
| SHA1: |
85e2badeeb7f7599eb6fd35512f9bd52 |
| User & Date: | drh 2014-07-24 20:25:16.037 |
Context
|
2014-07-24
| ||
| 23:23 | Improve the performance of the ANALYZE command by taking advantage of UNIQUE constraints on indices. (check-in: 114dcf3367 user: drh tags: trunk) | |
| 20:25 | Avoid trying to allocation zero bytes when analyzing a unique non-null index. (Closed-Leaf check-in: 85e2badeeb user: drh tags: faster-analyze) | |
| 19:54 | Avoid change tests when analyzing single-column unique indexes after getting past the initial NULL entries. (check-in: 4690e99c07 user: drh tags: faster-analyze) | |
Changes
Changes to src/analyze.c.
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iIdxCur = iTab++;
pParse->nTab = MAX(pParse->nTab, iTab);
sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead);
sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0);
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
int nCol; /* Number of columns in pIdx. "N" */
| < < < | 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 |
iIdxCur = iTab++;
pParse->nTab = MAX(pParse->nTab, iTab);
sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead);
sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0);
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
int nCol; /* Number of columns in pIdx. "N" */
int addrRewind; /* Address of "OP_Rewind iIdxCur" */
int addrNextRow; /* Address of "next_row:" */
const char *zIdxName; /* Name of the index */
int nColTest; /* Number of columns to test for changes */
if( pOnlyIdx && pOnlyIdx!=pIdx ) continue;
if( pIdx->pPartIdxWhere==0 ) needTableCnt = 0;
if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIdx) ){
nCol = pIdx->nKeyCol;
zIdxName = pTab->zName;
nColTest = nCol - 1;
}else{
nCol = pIdx->nColumn;
zIdxName = pIdx->zName;
nColTest = pIdx->uniqNotNull ? pIdx->nKeyCol-1 : nCol-1;
}
/* Populate the register containing the index name. */
sqlite3VdbeAddOp4(v, OP_String8, 0, regIdxname, 0, zIdxName, 0);
VdbeComment((v, "Analysis for %s.%s", pTab->zName, zIdxName));
/*
** Pseudo-code for loop that calls stat_push():
|
| ︙ | ︙ | |||
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addrRewind = sqlite3VdbeAddOp1(v, OP_Rewind, iIdxCur);
VdbeCoverage(v);
sqlite3VdbeAddOp2(v, OP_Integer, 0, regChng);
addrNextRow = sqlite3VdbeCurrentAddr(v);
if( nColTest>0 ){
int endDistinctTest = sqlite3VdbeMakeLabel(v);
/*
** next_row:
** regChng = 0
** if( idx(0) != regPrev(0) ) goto chng_addr_0
** regChng = 1
** if( idx(1) != regPrev(1) ) goto chng_addr_1
** ...
| > > > > | 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 |
addrRewind = sqlite3VdbeAddOp1(v, OP_Rewind, iIdxCur);
VdbeCoverage(v);
sqlite3VdbeAddOp2(v, OP_Integer, 0, regChng);
addrNextRow = sqlite3VdbeCurrentAddr(v);
if( nColTest>0 ){
int endDistinctTest = sqlite3VdbeMakeLabel(v);
int *aGotoChng; /* Array of jump instruction addresses */
aGotoChng = sqlite3DbMallocRaw(db, sizeof(int)*nColTest);
if( aGotoChng==0 ) continue;
/*
** next_row:
** regChng = 0
** if( idx(0) != regPrev(0) ) goto chng_addr_0
** regChng = 1
** if( idx(1) != regPrev(1) ) goto chng_addr_1
** ...
|
| ︙ | ︙ | |||
1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 |
*/
sqlite3VdbeJumpHere(v, addrNextRow-1);
for(i=0; i<nColTest; i++){
sqlite3VdbeJumpHere(v, aGotoChng[i]);
sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regPrev+i);
}
sqlite3VdbeResolveLabel(v, endDistinctTest);
}
/*
** chng_addr_N:
** regRowid = idx(rowid) // STAT34 only
** stat_push(P, regChng, regRowid) // 3rd parameter STAT34 only
** Next csr
| > | 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 |
*/
sqlite3VdbeJumpHere(v, addrNextRow-1);
for(i=0; i<nColTest; i++){
sqlite3VdbeJumpHere(v, aGotoChng[i]);
sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regPrev+i);
}
sqlite3VdbeResolveLabel(v, endDistinctTest);
sqlite3DbFree(db, aGotoChng);
}
/*
** chng_addr_N:
** regRowid = idx(rowid) // STAT34 only
** stat_push(P, regChng, regRowid) // 3rd parameter STAT34 only
** Next csr
|
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sqlite3VdbeAddOp2(v, OP_Goto, 1, addrNext); /* P1==1 for end-of-loop */
sqlite3VdbeJumpHere(v, addrIsNull);
}
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
/* End of analysis */
sqlite3VdbeJumpHere(v, addrRewind);
| < | 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 |
sqlite3VdbeAddOp2(v, OP_Goto, 1, addrNext); /* P1==1 for end-of-loop */
sqlite3VdbeJumpHere(v, addrIsNull);
}
#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
/* End of analysis */
sqlite3VdbeJumpHere(v, addrRewind);
}
/* Create a single sqlite_stat1 entry containing NULL as the index
** name and the row count as the content.
*/
if( pOnlyIdx==0 && needTableCnt ){
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| ︙ | ︙ |