Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Reduce the performance cost of the constant propagation optimization to less than 200,000 cycles. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | propagate-const-opt |
| Files: | files | file ages | folders |
| SHA3-256: | 865249de683e6971984a645a30d96f9f |
| User & Date: | drh 2018-07-27 20:01:00 |
Context
|
2018-07-27
| ||
| 20:37 | The WHERE-clause constant propagation optimization attempts to use transitive laws to replace column values with constants in the WHERE clause in order to help to query planner make more aggressive optimizations. check-in: f4229707 user: drh tags: trunk | |
| 20:01 | Reduce the performance cost of the constant propagation optimization to less than 200,000 cycles. Closed-Leaf check-in: 865249de user: drh tags: propagate-const-opt | |
| 18:19 | Performance improvement to sqlite3ExprCollSeq(). With this change, the performance of speed-check.sh is within 400,000 cycles of trunk. check-in: a5f86f49 user: drh tags: propagate-const-opt | |
Changes
Changes to src/select.c.
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
....
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
|
** Add a new entry to the pConst object
*/
static void constInsert(
WhereConst *pConst,
Expr *pColumn,
Expr *pValue
){
pConst->nConst++;
pConst->apExpr = sqlite3DbReallocOrFree(pConst->pParse->db, pConst->apExpr,
pConst->nConst*2*sizeof(Expr*));
if( pConst->apExpr==0 ){
pConst->nConst = 0;
}else{
if( ExprHasProperty(pValue, EP_FixedCol) ) pValue = pValue->pLeft;
................................................................................
** Find all terms of COLUMN=VALUE or VALUE=COLUMN in pExpr where VALUE
** is a constant expression and where the term must be true because it
** is part of the AND-connected terms of the expression. For each term
** found, add it to the pConst structure.
*/
static void findConstInWhere(WhereConst *pConst, Expr *pExpr){
Expr *pRight, *pLeft;
CollSeq *pColl;
if( pExpr==0 ) return;
if( ExprHasProperty(pExpr, EP_FromJoin) ) return;
if( pExpr->op==TK_AND ){
findConstInWhere(pConst, pExpr->pRight);
findConstInWhere(pConst, pExpr->pLeft);
return;
}
if( pExpr->op!=TK_EQ ) return;
pRight = pExpr->pRight;
pLeft = pExpr->pLeft;
assert( pRight!=0 );
assert( pLeft!=0 );
pColl = sqlite3BinaryCompareCollSeq(pConst->pParse, pLeft, pRight);
if( !sqlite3IsBinary(pColl) ) return;
if( pRight->op==TK_COLUMN
&& !ExprHasProperty(pRight, EP_FixedCol)
&& sqlite3ExprIsConstant(pLeft)
){
constInsert(pConst, pRight, pLeft);
}else
if( pLeft->op==TK_COLUMN
&& !ExprHasProperty(pLeft, EP_FixedCol)
&& sqlite3ExprIsConstant(pRight) ){
constInsert(pConst, pLeft, pRight);
}
}
/*
** This is a Walker expression callback. pExpr is a candidate expression
** to be replaced by a value. If pExpr is equivalent to one of the
|
>
<
<
<
>
|
>
>
|
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
....
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
|
** Add a new entry to the pConst object
*/
static void constInsert(
WhereConst *pConst,
Expr *pColumn,
Expr *pValue
){
pConst->nConst++;
pConst->apExpr = sqlite3DbReallocOrFree(pConst->pParse->db, pConst->apExpr,
pConst->nConst*2*sizeof(Expr*));
if( pConst->apExpr==0 ){
pConst->nConst = 0;
}else{
if( ExprHasProperty(pValue, EP_FixedCol) ) pValue = pValue->pLeft;
................................................................................
** Find all terms of COLUMN=VALUE or VALUE=COLUMN in pExpr where VALUE
** is a constant expression and where the term must be true because it
** is part of the AND-connected terms of the expression. For each term
** found, add it to the pConst structure.
*/
static void findConstInWhere(WhereConst *pConst, Expr *pExpr){
Expr *pRight, *pLeft;
if( pExpr==0 ) return;
if( ExprHasProperty(pExpr, EP_FromJoin) ) return;
if( pExpr->op==TK_AND ){
findConstInWhere(pConst, pExpr->pRight);
findConstInWhere(pConst, pExpr->pLeft);
return;
}
if( pExpr->op!=TK_EQ ) return;
pRight = pExpr->pRight;
pLeft = pExpr->pLeft;
assert( pRight!=0 );
assert( pLeft!=0 );
if( pRight->op==TK_COLUMN
&& !ExprHasProperty(pRight, EP_FixedCol)
&& sqlite3ExprIsConstant(pLeft)
&& sqlite3IsBinary(sqlite3BinaryCompareCollSeq(pConst->pParse,pLeft,pRight))
){
constInsert(pConst, pRight, pLeft);
}else
if( pLeft->op==TK_COLUMN
&& !ExprHasProperty(pLeft, EP_FixedCol)
&& sqlite3ExprIsConstant(pRight)
&& sqlite3IsBinary(sqlite3BinaryCompareCollSeq(pConst->pParse,pLeft,pRight))
){
constInsert(pConst, pLeft, pRight);
}
}
/*
** This is a Walker expression callback. pExpr is a candidate expression
** to be replaced by a value. If pExpr is equivalent to one of the
|