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Overview
| Comment: | Remove an incorrect NEVER() reported at forum post 5bbabfb7ce. Also use this opportunity to improve the isSimpleCount() function with better formatting, an expanded header comment, and some extra assert() and textcase() macros. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA3-256: |
2927185be81a5aa0dce70dd06040d05c |
| User & Date: | drh 2021-11-05 11:52:33 |
Context
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2021-11-05
| ||
| 12:34 | Use the FTS_CORRUPT_VTAB macro rather than a direct call to sqlite3Fts3Corrupt() in [2fad2a89527757b3] so that the build works in all cases. (check-in: 029c59cd user: drh tags: trunk) | |
| 11:52 | Remove an incorrect NEVER() reported at forum post 5bbabfb7ce. Also use this opportunity to improve the isSimpleCount() function with better formatting, an expanded header comment, and some extra assert() and textcase() macros. (check-in: 2927185b user: drh tags: trunk) | |
| 11:26 | Fix vacuum3.test so that it works with SQLITE_OMIT_ALTERTABLE builds. (check-in: 07cca2fa user: dan tags: trunk) | |
Changes
Changes to src/select.c.
| ︙ | ︙ | |||
4944 4945 4946 4947 4948 4949 4950 | ** The second argument is the associated aggregate-info object. This ** function tests if the SELECT is of the form: ** ** SELECT count(*) FROM <tbl> ** ** where table is a database table, not a sub-select or view. If the query ** does match this pattern, then a pointer to the Table object representing | | > > > > > > | > | > > < | | | > > < > > > | 4944 4945 4946 4947 4948 4949 4950 4951 4952 4953 4954 4955 4956 4957 4958 4959 4960 4961 4962 4963 4964 4965 4966 4967 4968 4969 4970 4971 4972 4973 4974 4975 4976 4977 4978 4979 4980 4981 4982 4983 4984 4985 4986 4987 4988 4989 4990 |
** The second argument is the associated aggregate-info object. This
** function tests if the SELECT is of the form:
**
** SELECT count(*) FROM <tbl>
**
** where table is a database table, not a sub-select or view. If the query
** does match this pattern, then a pointer to the Table object representing
** <tbl> is returned. Otherwise, NULL is returned.
**
** This routine a condition for the count optimization. A correct answer
** is obtained (though perhaps more slowly) if this routine returns NULL when
** it could have returned a table pointer. But returning the pointer when
** NULL should have been returned can result in incorrect answers and/or
** crashes. So, when in doubt, return NULL.
*/
static Table *isSimpleCount(Select *p, AggInfo *pAggInfo){
Table *pTab;
Expr *pExpr;
assert( !p->pGroupBy );
if( p->pWhere
|| p->pEList->nExpr!=1
|| p->pSrc->nSrc!=1
|| p->pSrc->a[0].pSelect
|| pAggInfo->nFunc!=1
){
return 0;
}
pTab = p->pSrc->a[0].pTab;
assert( pTab!=0 );
assert( !IsView(pTab) );
if( !IsOrdinaryTable(pTab) ) return 0;
pExpr = p->pEList->a[0].pExpr;
assert( pExpr!=0 );
if( pExpr->op!=TK_AGG_FUNCTION ) return 0;
if( (pAggInfo->aFunc[0].pFunc->funcFlags&SQLITE_FUNC_COUNT)==0 ) return 0;
assert( pAggInfo->aFunc[0].pFExpr==pExpr );
testcase( ExprHasProperty(pExpr, EP_Distinct) );
testcase( ExprHasProperty(pExpr, EP_WinFunc) );
if( ExprHasProperty(pExpr, EP_Distinct|EP_WinFunc) ) return 0;
return pTab;
}
/*
** If the source-list item passed as an argument was augmented with an
|
| ︙ | ︙ |