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MWL#68 Subquery optimization: Efficient NOT IN execution with NULLs

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This patch does three things:
- It adds the possibility to force the execution of top-level [NOT] IN
  subquery predicates via the IN=>EXISTS transformation. This is done by
  setting both optimizer switches partial_match_rowid_merge and
  partial_match_table_scan to "off".
- It adjusts all test cases where the complete optimizer_switch is
  selected because now we have two more switches.
- For those test cases where the plan changes because of the new available
  strategies, we switch off both partial match strategies in order to
  force the "old" IN=>EXISTS strategy. This is done because most of these
  test cases specifically test bugs in this strategy.

sql/opt_subselect.cc:
  Adds the possibility to force the execution of top-level [NOT] IN
  subquery predicates via the IN=>EXISTS transformation. This is done by
  setting both optimizer switches partial_match_rowid_merge and
  partial_match_table_scan to "off".
This commit is contained in:
unknown
2010-03-11 23:43:31 +02:00
parent 292d466749
commit 3d2a74609a
17 changed files with 105 additions and 46 deletions
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3
mysql-test/r/innodb_mysql.result
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@ -1425,12 +1425,15 @@ DROP TABLE t1;
#
create table t1 (a bit(1) not null,b int) engine=myisam;
create table t2 (c int) engine=innodb;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=off';
explain
select b from t1 where a not in (select b from t1,t2 group by a) group by a;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
2 DEPENDENT SUBQUERY t1 system NULL NULL NULL NULL 0 const row not found
2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 1
set optimizer_switch=@save_optimizer_switch;
DROP TABLE t1,t2;
End of 5.0 tests
CREATE TABLE `t2` (