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Overview
| Comment: | Ensure that automatic indexes are only created in scenarios where they may be used more than once. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
27c65d4d9c58bfc4ea8f9337fa150904 |
| User & Date: | dan 2011-07-02 15:32:57 |
References
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2011-07-02
| ||
| 15:42 | Cherrypick change [27c65d4d9c] into the 3.7.2 branch. (check-in: 9bbcd8c0 user: dan tags: branch-3.7.2) | |
Context
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2011-07-02
| ||
| 19:12 | Add a testcase macro to ensure testing a boundary case in DISTINCT processing. (check-in: ff9fc722 user: drh tags: trunk) | |
| 15:32 | Ensure that automatic indexes are only created in scenarios where they may be used more than once. (check-in: 27c65d4d user: dan tags: trunk) | |
| 09:46 | Merge experimental changes improving optimization of DISTINCT queries with the trunk. (check-in: 45e581bf user: dan tags: trunk) | |
Changes
Changes to src/where.c.
| ︙ | ︙ | |||
1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 |
double nTableRow; /* Rows in the input table */
double logN; /* log(nTableRow) */
double costTempIdx; /* per-query cost of the transient index */
WhereTerm *pTerm; /* A single term of the WHERE clause */
WhereTerm *pWCEnd; /* End of pWC->a[] */
Table *pTable; /* Table tht might be indexed */
if( (pParse->db->flags & SQLITE_AutoIndex)==0 ){
/* Automatic indices are disabled at run-time */
return;
}
if( (pCost->plan.wsFlags & WHERE_NOT_FULLSCAN)!=0 ){
/* We already have some kind of index in use for this query. */
return;
| > > > > | 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 |
double nTableRow; /* Rows in the input table */
double logN; /* log(nTableRow) */
double costTempIdx; /* per-query cost of the transient index */
WhereTerm *pTerm; /* A single term of the WHERE clause */
WhereTerm *pWCEnd; /* End of pWC->a[] */
Table *pTable; /* Table tht might be indexed */
if( pParse->nQueryLoop<=(double)1 ){
/* There is no point in building an automatic index for a single scan */
return;
}
if( (pParse->db->flags & SQLITE_AutoIndex)==0 ){
/* Automatic indices are disabled at run-time */
return;
}
if( (pCost->plan.wsFlags & WHERE_NOT_FULLSCAN)!=0 ){
/* We already have some kind of index in use for this query. */
return;
|
| ︙ | ︙ |
Changes to test/autoindex1.test.
| ︙ | ︙ | |||
243 244 245 246 247 248 249 250 251 |
1 0 0 {SCAN TABLE sheep AS s (~1000000 rows)}
1 1 1 {SEARCH TABLE flock_owner AS prev USING INDEX sqlite_autoindex_flock_owner_1 (flock_no=? AND owner_change_date<?) (~2 rows)}
1 0 0 {EXECUTE CORRELATED SCALAR SUBQUERY 2}
2 0 0 {SEARCH TABLE flock_owner AS later USING COVERING INDEX sqlite_autoindex_flock_owner_1 (flock_no=? AND owner_change_date>? AND owner_change_date<?) (~1 rows)}
0 0 0 {SCAN TABLE sheep AS x USING INDEX sheep_reg_flock_index (~1000000 rows)}
0 1 1 {SEARCH SUBQUERY 1 AS y USING AUTOMATIC COVERING INDEX (sheep_no=?) (~8 rows)}
}
finish_test
| > > > > > > > > > > | 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 |
1 0 0 {SCAN TABLE sheep AS s (~1000000 rows)}
1 1 1 {SEARCH TABLE flock_owner AS prev USING INDEX sqlite_autoindex_flock_owner_1 (flock_no=? AND owner_change_date<?) (~2 rows)}
1 0 0 {EXECUTE CORRELATED SCALAR SUBQUERY 2}
2 0 0 {SEARCH TABLE flock_owner AS later USING COVERING INDEX sqlite_autoindex_flock_owner_1 (flock_no=? AND owner_change_date>? AND owner_change_date<?) (~1 rows)}
0 0 0 {SCAN TABLE sheep AS x USING INDEX sheep_reg_flock_index (~1000000 rows)}
0 1 1 {SEARCH SUBQUERY 1 AS y USING AUTOMATIC COVERING INDEX (sheep_no=?) (~8 rows)}
}
do_execsql_test autoindex1-700 {
CREATE TABLE t5(a, b, c);
EXPLAIN QUERY PLAN SELECT a FROM t5 WHERE b=10 ORDER BY c;
} {
0 0 0 {SCAN TABLE t5 (~100000 rows)}
0 0 0 {USE TEMP B-TREE FOR ORDER BY}
}
finish_test
|