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Overview
| Comment: | Fix the typeof() and length() optimization so that it works for aggregates as well as scalar queries. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | faster-typeof-and-length |
| Files: | files | file ages | folders |
| SHA1: | bc18215a8a660442db6ddeeda4a88df0 |
| User & Date: | drh 2012-03-28 02:43:20 |
Context
|
2012-03-28
| ||
| 02:51 | Test cases for length() of a large blob in an aggregate query. check-in: d095fa4b user: drh tags: faster-typeof-and-length | |
| 02:43 | Fix the typeof() and length() optimization so that it works for aggregates as well as scalar queries. check-in: bc18215a user: drh tags: faster-typeof-and-length | |
| 01:34 | Evaluate typeof(X) and length(Y) where X is any column and Y is a blob column without actually loading X and Y from disk. check-in: b899dbeb user: drh tags: faster-typeof-and-length | |
Changes
Changes to src/expr.c.
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/* For length() and typeof() functions with a column argument,
** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
** or OPFLAG_TYPEOFARG respectively, to avoid unnecessary data
** loading.
*/
if( (pDef->flags & (SQLITE_FUNC_LENGTH|SQLITE_FUNC_TYPEOF))!=0 ){
assert( nFarg==1 );
assert( pFarg->a[0].pExpr!=0 );
if( pFarg->a[0].pExpr->op==TK_COLUMN ){
assert( SQLITE_FUNC_LENGTH==OPFLAG_LENGTHARG );
assert( SQLITE_FUNC_TYPEOF==OPFLAG_TYPEOFARG );
testcase( pDef->flags==SQLITE_FUNC_LENGTH );
pFarg->a[0].pExpr->op2 = pDef->flags;
}
}
|
> | > |
2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 |
/* For length() and typeof() functions with a column argument,
** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
** or OPFLAG_TYPEOFARG respectively, to avoid unnecessary data
** loading.
*/
if( (pDef->flags & (SQLITE_FUNC_LENGTH|SQLITE_FUNC_TYPEOF))!=0 ){
u8 op;
assert( nFarg==1 );
assert( pFarg->a[0].pExpr!=0 );
op = pFarg->a[0].pExpr->op;
if( op==TK_COLUMN || op==TK_AGG_COLUMN ){
assert( SQLITE_FUNC_LENGTH==OPFLAG_LENGTHARG );
assert( SQLITE_FUNC_TYPEOF==OPFLAG_TYPEOFARG );
testcase( pDef->flags==SQLITE_FUNC_LENGTH );
pFarg->a[0].pExpr->op2 = pDef->flags;
}
}
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