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bug #27531: 5.1 part of the fix:

Browse Source 
- added join cache indication in EXPLAIN (Extra column).
 - prefer filesort over full scan over 
   index for ORDER BY (because it's faster).
 - when switching from REF to RANGE because
   RANGE uses longer key turn off sort on
   the head table only as the resulting 
   RANGE access is a candidate for join cache
   and we don't want to disable it by sorting
   on the first table only. 


mysql-test/r/archive_gis.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/compress.result:
  bug #27531:
   - join cache in EXPLAIN. 
   - prefer filesort over full scan over index for ORDER BY.
mysql-test/r/ctype_utf8.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/derived.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/distinct.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/func_group.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/func_group_innodb.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/gis.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/greedy_optimizer.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/group_by.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/group_min_max.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/index_merge_myisam.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/information_schema.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/innodb_gis.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/innodb_mysql.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/join.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/join_nested.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/key_diff.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/myisam.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/ndb_condition_pushdown.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/ndb_gis.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/range.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/row.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/select.result:
  bug #27531:
   - join cache in EXPLAIN.
   - prefer filesort over full scan over index for ORDER BY.
mysql-test/r/ssl.result:
  bug #27531:
   - join cache in EXPLAIN.
   - prefer filesort over full scan over index for ORDER BY.
mysql-test/r/ssl_compress.result:
  bug #27531:
   - join cache in EXPLAIN.
   - prefer filesort over full scan over index for ORDER BY.
mysql-test/r/subselect.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/subselect3.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/union.result:
  bug #27531: join cache in EXPLAIN
mysql-test/r/view.result:
  bug #27531: join cache in EXPLAIN
sql/sql_select.cc:
  bug #27531:
   - join cache in EXPLAIN.
   - prefer filesort over full scan over
     index for ORDER BY.
   - disable sorting on the first table only
     when switching from REF to RANGE.
This commit is contained in:
unknown
2007-05-04 18:06:06 +03:00
parent 27aeb9e02b
commit 0c835da803
31 changed files with 216 additions and 202 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
mysql-test/r/distinct.result
View File

@ -174,7 +174,7 @@ INSERT INTO t3 VALUES (1,'1'),(2,'2'),(1,'1'),(2,'2');
explain SELECT distinct t3.a FROM t3,t2,t1 WHERE t3.a=t1.b AND t1.a=t2.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL PRIMARY NULL NULL NULL 4 Using temporary
1 SIMPLE t3 ref a a 5 test.t1.b 2 Using where; Using index
1 SIMPLE t3 ref a a 5 test.t1.b 2 Using where; Using index; Using join cache
1 SIMPLE t2 index a a 4 NULL 5 Using where; Using index; Distinct
SELECT distinct t3.a FROM t3,t2,t1 WHERE t3.a=t1.b AND t1.a=t2.a;
a
@ -299,11 +299,11 @@ WHERE
((t1.id=j_lj_t2.id AND t2_lj.id IS NULL) OR (t1.id=t2.id AND t2.idx=2))
AND ((t1.id=j_lj_t3.id AND t3_lj.id IS NULL) OR (t1.id=t3.id AND t3.idx=2));
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index id id 4 NULL 2 Using index; Using temporary
1 SIMPLE t2 index id id 8 NULL 1 Using index; Distinct
1 SIMPLE t3 index id id 8 NULL 1 Using index; Distinct
1 SIMPLE t1 index id id 4 NULL 2 Using index; Using temporary; Using join cache
1 SIMPLE t2 index id id 8 NULL 1 Using index; Distinct; Using join cache
1 SIMPLE t3 index id id 8 NULL 1 Using index; Distinct; Using join cache
1 SIMPLE j_lj_t2 index id id 4 NULL 2 Using where; Using index; Distinct
1 SIMPLE t2_lj ref id id 4 test.j_lj_t2.id 1 Using where; Using index; Distinct
1 SIMPLE t2_lj ref id id 4 test.j_lj_t2.id 1 Using where; Using index; Distinct; Using join cache
1 SIMPLE j_lj_t3 index id id 4 NULL 2 Using where; Using index; Distinct
1 SIMPLE t3_lj ref id id 4 test.j_lj_t3.id 1 Using where; Using index; Distinct
SELECT DISTINCT
@ -514,7 +514,7 @@ id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 3
EXPLAIN SELECT DISTINCT t1_1.a, t1_1.b FROM t1 t1_1, t1 t1_2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1_1 ALL NULL NULL NULL NULL 3 Using temporary
1 SIMPLE t1_1 ALL NULL NULL NULL NULL 3 Using temporary; Using join cache
1 SIMPLE t1_2 index NULL PRIMARY 4 NULL 3 Using index; Distinct
EXPLAIN SELECT DISTINCT t1_1.a, t1_1.b FROM t1 t1_1, t1 t1_2
WHERE t1_1.a = t1_2.a;