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Bug #21174: Index degrades sort performance and optimizer does not honor IGNORE INDEX

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- reversed the patch for 5.0 and moved to 5.1
This commit is contained in:
gkodinov/kgeorge@macbook.gmz
2006-09-27 12:53:53 +03:00
parent 542cdbbc42
commit 903387afc0
3 changed files with 0 additions and 23 deletions
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9
mysql-test/r/group_by.result
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@ -821,12 +821,3 @@ a b real_b
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DROP VIEW v1; DROP VIEW v1;
DROP TABLE t1,t2; DROP TABLE t1,t2;
CREATE TABLE t1 (a INT, b INT, KEY(a));
INSERT INTO t1 VALUES (1, 1), (2, 2), (3,3), (4,4);
EXPLAIN SELECT a, SUM(b) FROM t1 GROUP BY a LIMIT 2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL a 5 NULL 4
EXPLAIN SELECT a, SUM(b) FROM t1 IGNORE INDEX (a) GROUP BY a LIMIT 2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 4 Using temporary; Using filesort
DROP TABLE t1;

12
mysql-test/t/group_by.test
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@ -655,15 +655,3 @@ where t2.b=v1.a GROUP BY t2.b;
DROP VIEW v1; DROP VIEW v1;
DROP TABLE t1,t2; DROP TABLE t1,t2;
#
# Bug #21174: Index degrades sort performance and
# optimizer does not honor IGNORE INDEX
#
CREATE TABLE t1 (a INT, b INT, KEY(a));
INSERT INTO t1 VALUES (1, 1), (2, 2), (3,3), (4,4);
EXPLAIN SELECT a, SUM(b) FROM t1 GROUP BY a LIMIT 2;
EXPLAIN SELECT a, SUM(b) FROM t1 IGNORE INDEX (a) GROUP BY a LIMIT 2;
DROP TABLE t1;

2
sql/sql_select.cc
View File

@ -11735,8 +11735,6 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
We must not try to use disabled keys. We must not try to use disabled keys.
*/ */
usable_keys= table->s->keys_in_use; usable_keys= table->s->keys_in_use;
/* we must not consider keys that are disabled by IGNORE INDEX */
usable_keys.intersect(table->keys_in_use_for_query);
for (ORDER *tmp_order=order; tmp_order ; tmp_order=tmp_order->next) for (ORDER *tmp_order=order; tmp_order ; tmp_order=tmp_order->next)
{ {