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Overview
| Comment: | Improved ORDER BY optimization for WITHOUT ROWID tables. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | omit-rowid |
| Files: | files | file ages | folders |
| SHA1: |
8f1709ff2d52d5ceca3da6a2a4e06da2 |
| User & Date: | drh 2013-11-06 12:56:04 |
Context
|
2013-11-06
| ||
| 14:05 | Minor optimization to the OP_Halt opcode. (check-in: d70c7881 user: drh tags: omit-rowid) | |
| 12:56 | Improved ORDER BY optimization for WITHOUT ROWID tables. (check-in: 8f1709ff user: drh tags: omit-rowid) | |
| 12:05 | Disable the OR optimization for WITHOUT ROWID tables, since it relies on the use of rowids. (check-in: 6055dad2 user: drh tags: omit-rowid) | |
Changes
Changes to src/where.c.
5020 5021 5022 5023 5024 5025 5026 5027 5028 5029 5030 5031 5032 5033 5034 .... 5113 5114 5115 5116 5117 5118 5119 5120 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131 5132 5133 5134 5135 5136 5137 5138 5139 .... 5142 5143 5144 5145 5146 5147 5148 5149 5150 5151 5152 5153 5154 5155 5156 5157 5158 5159 5160 5161 5162 5163 5164 5165 5166 5167 5168 5169 |
){
u8 revSet; /* True if rev is known */
u8 rev; /* Composite sort order */
u8 revIdx; /* Index sort order */
u8 isOrderDistinct; /* All prior WhereLoops are order-distinct */
u8 distinctColumns; /* True if the loop has UNIQUE NOT NULL columns */
u8 isMatch; /* iColumn matches a term of the ORDER BY clause */
u16 nKeyCol; /* Number of columns in pIndex */
u16 nOrderBy; /* Number terms in the ORDER BY clause */
int iLoop; /* Index of WhereLoop in pPath being processed */
int i, j; /* Loop counters */
int iCur; /* Cursor number for current WhereLoop */
int iColumn; /* A column number within table iCur */
WhereLoop *pLoop = 0; /* Current WhereLoop being processed. */
WhereTerm *pTerm; /* A single term of the WHERE clause */
................................................................................
obSat |= MASKBIT(i);
}
if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){
if( pLoop->wsFlags & WHERE_IPK ){
pIndex = 0;
nKeyCol = 0;
}else if( (pIndex = pLoop->u.btree.pIndex)==0 || pIndex->bUnordered ){
return 0;
}else{
nKeyCol = pIndex->nKeyCol;
isOrderDistinct = pIndex->onError!=OE_None;
}
/* Loop through all columns of the index and deal with the ones
** that are not constrained by == or IN.
*/
rev = revSet = 0;
distinctColumns = 0;
for(j=0; j<=nKeyCol; j++){
u8 bOnce; /* True to run the ORDER BY search loop */
/* Skip over == and IS NULL terms */
if( j<pLoop->u.btree.nEq
&& ((i = pLoop->aLTerm[j]->eOperator) & (WO_EQ|WO_ISNULL))!=0
){
if( i & WO_ISNULL ){
................................................................................
}
continue;
}
/* Get the column number in the table (iColumn) and sort order
** (revIdx) for the j-th column of the index.
*/
if( j<nKeyCol ){
/* Normal index columns */
iColumn = pIndex->aiColumn[j];
revIdx = pIndex->aSortOrder[j];
if( iColumn==pIndex->pTable->iPKey ) iColumn = -1;
}else{
/* The ROWID column at the end */
assert( j==nKeyCol );
iColumn = -1;
revIdx = 0;
}
/* An unconstrained column that might be NULL means that this
** WhereLoop is not well-ordered
*/
if( isOrderDistinct
&& iColumn>=0
&& j>=pLoop->u.btree.nEq
&& pIndex->pTable->aCol[iColumn].notNull==0
){
isOrderDistinct = 0;
|
| > > > > > | | < < < | |
5020 5021 5022 5023 5024 5025 5026 5027 5028 5029 5030 5031 5032 5033 5034 5035 .... 5114 5115 5116 5117 5118 5119 5120 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131 5132 5133 5134 5135 5136 5137 5138 5139 5140 5141 5142 5143 5144 .... 5147 5148 5149 5150 5151 5152 5153 5154 5155 5156 5157 5158 5159 5160 5161 5162 5163 5164 5165 5166 5167 5168 5169 5170 5171 |
){
u8 revSet; /* True if rev is known */
u8 rev; /* Composite sort order */
u8 revIdx; /* Index sort order */
u8 isOrderDistinct; /* All prior WhereLoops are order-distinct */
u8 distinctColumns; /* True if the loop has UNIQUE NOT NULL columns */
u8 isMatch; /* iColumn matches a term of the ORDER BY clause */
u16 nKeyCol; /* Number of key columns in pIndex */
u16 nColumn; /* Total number of ordered columns in the index */
u16 nOrderBy; /* Number terms in the ORDER BY clause */
int iLoop; /* Index of WhereLoop in pPath being processed */
int i, j; /* Loop counters */
int iCur; /* Cursor number for current WhereLoop */
int iColumn; /* A column number within table iCur */
WhereLoop *pLoop = 0; /* Current WhereLoop being processed. */
WhereTerm *pTerm; /* A single term of the WHERE clause */
................................................................................
obSat |= MASKBIT(i);
}
if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){
if( pLoop->wsFlags & WHERE_IPK ){
pIndex = 0;
nKeyCol = 0;
nColumn = 1;
}else if( (pIndex = pLoop->u.btree.pIndex)==0 || pIndex->bUnordered ){
return 0;
}else{
nKeyCol = pIndex->nKeyCol;
nColumn = pIndex->nColumn;
assert( nColumn==nKeyCol+1 || !HasRowid(pIndex->pTable) );
assert( pIndex->aiColumn[nColumn-1]==(-1) || !HasRowid(pIndex->pTable));
isOrderDistinct = pIndex->onError!=OE_None;
}
/* Loop through all columns of the index and deal with the ones
** that are not constrained by == or IN.
*/
rev = revSet = 0;
distinctColumns = 0;
for(j=0; j<nColumn; j++){
u8 bOnce; /* True to run the ORDER BY search loop */
/* Skip over == and IS NULL terms */
if( j<pLoop->u.btree.nEq
&& ((i = pLoop->aLTerm[j]->eOperator) & (WO_EQ|WO_ISNULL))!=0
){
if( i & WO_ISNULL ){
................................................................................
}
continue;
}
/* Get the column number in the table (iColumn) and sort order
** (revIdx) for the j-th column of the index.
*/
if( pIndex ){
iColumn = pIndex->aiColumn[j];
revIdx = pIndex->aSortOrder[j];
if( iColumn==pIndex->pTable->iPKey ) iColumn = -1;
}else{
iColumn = -1;
revIdx = 0;
}
/* An unconstrained column that might be NULL means that this
** WhereLoop is not well-ordered
*/
if( isOrderDistinct
&& iColumn>=0
&& j>=pLoop->u.btree.nEq
&& pIndex->pTable->aCol[iColumn].notNull==0
){
isOrderDistinct = 0;
|
Changes to test/orderby5.test.
89 90 91 92 93 94 95 96 97 |
SELECT * FROM t1 WHERE a=0 ORDER BY c, a, b;
} {/B-TREE/}
do_execsql_test 2.7 {
EXPLAIN QUERY PLAN
SELECT * FROM t1 WHERE a=0 ORDER BY c, b, a;
} {/B-TREE/}
finish_test
|
> > > > > > > > > > > > > > > |
89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 |
SELECT * FROM t1 WHERE a=0 ORDER BY c, a, b;
} {/B-TREE/}
do_execsql_test 2.7 {
EXPLAIN QUERY PLAN
SELECT * FROM t1 WHERE a=0 ORDER BY c, b, a;
} {/B-TREE/}
do_execsql_test 3.0 {
CREATE TABLE t3(a INTEGER PRIMARY KEY, b, c, d, e, f);
CREATE INDEX t3bcde ON t3(b, c, d, e);
EXPLAIN QUERY PLAN
SELECT a FROM t3 WHERE b=2 AND c=3 ORDER BY d DESC, e DESC, b, c, a DESC;
} {~/B-TREE/}
do_execsql_test 3.1 {
DROP TABLE t3;
CREATE TABLE t3(a INTEGER PRIMARY KEY, b, c, d, e, f) WITHOUT rowid;
CREATE INDEX t3bcde ON t3(b, c, d, e);
EXPLAIN QUERY PLAN
SELECT a FROM t3 WHERE b=2 AND c=3 ORDER BY d DESC, e DESC, b, c, a DESC;
} {~/B-TREE/}
finish_test
|