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LP BUG#823169 fix.

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For ANY subqueries NULLs should be ignored (if there is other values) when finding max min.
For ALL subqueries NULLs should be saved if they found.

Optimisation for ALL suqbueries if NULL is possible in the SELECT list with max/min aggregate function switched off.

Some test changed where NULL is not used but optimization with max/min aggregate function important so NOT NULL added.

mysql-test/r/explain.result:
  Forced old optimization.
mysql-test/r/subselect.result:
  Forced old optimization.
  
  New test suite.
mysql-test/t/explain.test:
  Forced old optimization.
mysql-test/t/subselect.test:
  Forced old optimization.
  
  New test suite.
sql/item_subselect.cc:
  Store converted subquery type.
  
  Switch off aggregate function optimisation for ALL and nulls.
sql/sql_class.cc:
  Fixed NULL comparison.
sql/sql_class.h:
  Store converted subquery type.
This commit is contained in:
unknown
2011-09-02 10:11:13 +03:00
parent 31c8c95bb2
commit 37a8497d49
7 changed files with 442 additions and 36 deletions
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6
sql/sql_class.h
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@ -2931,9 +2931,11 @@ class select_max_min_finder_subselect :public select_subselect
Item_cache *cache;
bool (select_max_min_finder_subselect::*op)();
bool fmax;
bool is_all;
public:
select_max_min_finder_subselect(Item_subselect *item_arg, bool mx)
:select_subselect(item_arg), cache(0), fmax(mx)
select_max_min_finder_subselect(Item_subselect *item_arg, bool mx,
bool all)
:select_subselect(item_arg), cache(0), fmax(mx), is_all(all)
{}
void cleanup();
int send_data(List<Item> &items);