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Bug #21302: Result not properly sorted when using an ORDER BY on a second

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table in a join
 The optimizer removes redundant columns in ORDER BY. It is considering 
redundant every reference to const table column, e.g b in :
create table t1 (a int, b int, primary key(a)); 
select 1 from t1 order by b where a = 1

But it must not remove references to const table columns if the 
const table is an outer table because there still can be 2 values :
the const value and NULL. e.g.:
create table t1 (a int, b int, primary key(a));
select t2.b c from t1 left join t1 t2 on (t1.a = t2.a and t2.a = 5) 
  order by c;


mysql-test/r/join_outer.result:
  Bug #21302: Result not properly sorted when using an ORDER BY on a second 
              table in a join
   - don't remove columns of const tables in ORDER BY if the const table 
     is an outer table.
mysql-test/r/order_by.result:
  Bug #21302: Result not properly sorted when using an ORDER BY on a second 
              table in a join
   - test case
mysql-test/t/order_by.test:
  Bug #21302: Result not properly sorted when using an ORDER BY on a second 
              table in a join
   - test case
sql/sql_select.cc:
  Bug #21302: Result not properly sorted when using an ORDER BY on a second 
              table in a join
   - don't remove columns of const tables in ORDER BY if the const table 
     is an outer table.
This commit is contained in:
unknown
2006-08-14 15:45:48 +03:00
parent 1cf65f311d
commit 06a302eff2
4 changed files with 72 additions and 2 deletions
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2
mysql-test/r/join_outer.result
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@ -735,7 +735,7 @@ explain select s.*, '*', m.*, (s.match_1_h - m.home) UUX from
(t2 s left join t1 m on m.match_id = 1)
order by m.match_id desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE s ALL NULL NULL NULL NULL 10
1 SIMPLE s ALL NULL NULL NULL NULL 10 Using temporary; Using filesort
1 SIMPLE m const match_id,match_id_2 match_id 1 const 1
explain select s.*, '*', m.*, (s.match_1_h - m.home) UUX from
(t2 s left join t1 m on m.match_id = 1)