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Overview
| Comment: | Performance optimization: Avoid calling convertCompoundSelecctToSubquery() on queries that do not use the UNION, EXCEPT, or INTERSECT operators. |
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| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
c589b2fed7beabc2337d701094c22635 |
| User & Date: | drh 2013-08-05 22:05:02.528 |
Context
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2013-08-06
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| 07:45 | More than double the speed of the resolveP2Values() routine in vdbeaux.c by moving from an extended if-else on every opcode to a switch. Opcodes are reordered in mkopcodesh.awk to put the switched opcodes close together, for additional performance and to reduce code footprint. (check-in: 924f7e4d7a user: drh tags: trunk) | |
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2013-08-05
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| 22:05 | Performance optimization: Avoid calling convertCompoundSelecctToSubquery() on queries that do not use the UNION, EXCEPT, or INTERSECT operators. (check-in: c589b2fed7 user: drh tags: trunk) | |
| 21:54 | For the vtshim module, always zero out the xChildDestroy function pointer after calling it. (check-in: 240f7252c6 user: mistachkin tags: trunk) | |
Changes
Changes to src/parse.y.
| ︙ | ︙ | |||
413 414 415 416 417 418 419 420 421 422 423 424 425 426 |
select(A) ::= oneselect(X). {A = X;}
%ifndef SQLITE_OMIT_COMPOUND_SELECT
select(A) ::= select(X) multiselect_op(Y) oneselect(Z). {
if( Z ){
Z->op = (u8)Y;
Z->pPrior = X;
}else{
sqlite3SelectDelete(pParse->db, X);
}
A = Z;
}
%type multiselect_op {int}
multiselect_op(A) ::= UNION(OP). {A = @OP;}
| > | 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 |
select(A) ::= oneselect(X). {A = X;}
%ifndef SQLITE_OMIT_COMPOUND_SELECT
select(A) ::= select(X) multiselect_op(Y) oneselect(Z). {
if( Z ){
Z->op = (u8)Y;
Z->pPrior = X;
if( Y!=TK_ALL ) pParse->hasCompound = 1;
}else{
sqlite3SelectDelete(pParse->db, X);
}
A = Z;
}
%type multiselect_op {int}
multiselect_op(A) ::= UNION(OP). {A = @OP;}
|
| ︙ | ︙ |
Changes to src/select.c.
| ︙ | ︙ | |||
3635 3636 3637 3638 3639 3640 3641 |
** If anything goes wrong, an error message is written into pParse.
** The calling function can detect the problem by looking at pParse->nErr
** and/or pParse->db->mallocFailed.
*/
static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){
Walker w;
memset(&w, 0, sizeof(w));
| < > > | > | 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 |
** If anything goes wrong, an error message is written into pParse.
** The calling function can detect the problem by looking at pParse->nErr
** and/or pParse->db->mallocFailed.
*/
static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){
Walker w;
memset(&w, 0, sizeof(w));
w.xExprCallback = exprWalkNoop;
w.pParse = pParse;
if( pParse->hasCompound ){
w.xSelectCallback = convertCompoundSelectToSubquery;
sqlite3WalkSelect(&w, pSelect);
}
w.xSelectCallback = selectExpander;
sqlite3WalkSelect(&w, pSelect);
}
#ifndef SQLITE_OMIT_SUBQUERY
/*
|
| ︙ | ︙ |
Changes to src/sqliteInt.h.
| ︙ | ︙ | |||
2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 | #define SF_UsesEphemeral 0x0008 /* Uses the OpenEphemeral opcode */ #define SF_Expanded 0x0010 /* sqlite3SelectExpand() called on this */ #define SF_HasTypeInfo 0x0020 /* FROM subqueries have Table metadata */ #define SF_UseSorter 0x0040 /* Sort using a sorter */ #define SF_Values 0x0080 /* Synthesized from VALUES clause */ #define SF_Materialize 0x0100 /* Force materialization of views */ #define SF_NestedFrom 0x0200 /* Part of a parenthesized FROM clause */ /* ** The results of a select can be distributed in several ways. The ** "SRT" prefix means "SELECT Result Type". */ #define SRT_Union 1 /* Store result as keys in an index */ | > | 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 | #define SF_UsesEphemeral 0x0008 /* Uses the OpenEphemeral opcode */ #define SF_Expanded 0x0010 /* sqlite3SelectExpand() called on this */ #define SF_HasTypeInfo 0x0020 /* FROM subqueries have Table metadata */ #define SF_UseSorter 0x0040 /* Sort using a sorter */ #define SF_Values 0x0080 /* Synthesized from VALUES clause */ #define SF_Materialize 0x0100 /* Force materialization of views */ #define SF_NestedFrom 0x0200 /* Part of a parenthesized FROM clause */ #define SF_MaybeConvert 0x0400 /* Need convertCompoundSelectToSubquery() */ /* ** The results of a select can be distributed in several ways. The ** "SRT" prefix means "SELECT Result Type". */ #define SRT_Union 1 /* Store result as keys in an index */ |
| ︙ | ︙ | |||
2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 | u8 nested; /* Number of nested calls to the parser/code generator */ u8 nTempReg; /* Number of temporary registers in aTempReg[] */ u8 nTempInUse; /* Number of aTempReg[] currently checked out */ u8 nColCache; /* Number of entries in aColCache[] */ u8 iColCache; /* Next entry in aColCache[] to replace */ u8 isMultiWrite; /* True if statement may modify/insert multiple rows */ u8 mayAbort; /* True if statement may throw an ABORT exception */ int aTempReg[8]; /* Holding area for temporary registers */ int nRangeReg; /* Size of the temporary register block */ int iRangeReg; /* First register in temporary register block */ int nErr; /* Number of errors seen */ int nTab; /* Number of previously allocated VDBE cursors */ int nMem; /* Number of memory cells used so far */ int nSet; /* Number of sets used so far */ | > | 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 | u8 nested; /* Number of nested calls to the parser/code generator */ u8 nTempReg; /* Number of temporary registers in aTempReg[] */ u8 nTempInUse; /* Number of aTempReg[] currently checked out */ u8 nColCache; /* Number of entries in aColCache[] */ u8 iColCache; /* Next entry in aColCache[] to replace */ u8 isMultiWrite; /* True if statement may modify/insert multiple rows */ u8 mayAbort; /* True if statement may throw an ABORT exception */ u8 hasCompound; /* Need to invoke convertCompoundSelectToSubquery() */ int aTempReg[8]; /* Holding area for temporary registers */ int nRangeReg; /* Size of the temporary register block */ int iRangeReg; /* First register in temporary register block */ int nErr; /* Number of errors seen */ int nTab; /* Number of previously allocated VDBE cursors */ int nMem; /* Number of memory cells used so far */ int nSet; /* Number of sets used so far */ |
| ︙ | ︙ |