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Overview
Comment: | Deactivate the DISTINCT in a SELECT on the right-hand side of an IN operator, since it should not make any difference in the output but dues consume extra memory and CPU time. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
f4cb53651b1e352fae7378878b830a90 |
User & Date: | drh 2014-07-31 15:44:44.199 |
References
2014-11-14
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15:25 | • New ticket [db87229497] Incorrect result when RHS of IN operator contains DISTINCT and LIMIT. (artifact: b959ab7a02 user: drh) | |
Context
2014-07-31
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17:35 | Fix a leaked database handle in pager2.test. (check-in: 47457b0488 user: dan tags: trunk) | |
15:44 | Deactivate the DISTINCT in a SELECT on the right-hand side of an IN operator, since it should not make any difference in the output but dues consume extra memory and CPU time. (check-in: f4cb53651b user: drh tags: trunk) | |
2014-07-30
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23:11 | Re-integrate the recent changes from the 'winMutex' branch back into the Win32 mutex subsystem. (check-in: 5360ecb0b8 user: mistachkin tags: trunk) | |
Changes
Changes to src/expr.c.
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1620 1621 1622 1623 1624 1625 1626 | sqlite3VdbeJumpHere(v, iAddr); } } } } if( eType==0 ){ | | | 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 | sqlite3VdbeJumpHere(v, iAddr); } } } } if( eType==0 ){ /* Could not find an existing table or index to use as the RHS b-tree. ** We will have to generate an ephemeral table to do the job. */ u32 savedNQueryLoop = pParse->nQueryLoop; int rMayHaveNull = 0; eType = IN_INDEX_EPH; if( prNotFound ){ *prNotFound = rMayHaveNull = ++pParse->nMem; |
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1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 | if( ExprHasProperty(pExpr, EP_xIsSelect) ){ /* Case 1: expr IN (SELECT ...) ** ** Generate code to write the results of the select into the temporary ** table allocated and opened above. */ SelectDest dest; ExprList *pEList; assert( !isRowid ); sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable); dest.affSdst = (u8)affinity; assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable ); | > | > > | | | 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 | if( ExprHasProperty(pExpr, EP_xIsSelect) ){ /* Case 1: expr IN (SELECT ...) ** ** Generate code to write the results of the select into the temporary ** table allocated and opened above. */ Select *pSelect = pExpr->x.pSelect; SelectDest dest; ExprList *pEList; assert( !isRowid ); sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable); dest.affSdst = (u8)affinity; assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable ); pSelect->iLimit = 0; testcase( pSelect->selFlags & SF_Distinct ); pSelect->selFlags &= ~SF_Distinct; testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */ if( sqlite3Select(pParse, pSelect, &dest) ){ sqlite3KeyInfoUnref(pKeyInfo); return 0; } pEList = pSelect->pEList; assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */ assert( pEList!=0 ); assert( pEList->nExpr>0 ); assert( sqlite3KeyInfoIsWriteable(pKeyInfo) ); pKeyInfo->aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft, pEList->a[0].pExpr); }else if( ALWAYS(pExpr->x.pList!=0) ){ |
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