Merge mysql.com:/home/hf/work/mysql-5.0.clean

into  mysql.com:/home/hf/work/mysql-5.1.clean


include/my_time.h:
  Auto merged
mysql-test/r/func_group.result:
  Auto merged
mysql-test/r/gis-rtree.result:
  Auto merged
mysql-test/r/order_by.result:
  Auto merged
mysql-test/r/subselect.result:
  Auto merged
mysql-test/r/type_datetime.result:
  Auto merged
mysql-test/r/udf.result:
  Auto merged
mysql-test/t/func_group.test:
  Auto merged
mysql-test/t/gis-rtree.test:
  Auto merged
mysql-test/t/type_datetime.test:
  Auto merged
mysql-test/t/udf.test:
  Auto merged
sql/field.cc:
  Auto merged
sql/field.h:
  Auto merged
sql/filesort.cc:
  Auto merged
sql/item.h:
  Auto merged
sql/item_cmpfunc.cc:
  Auto merged
sql/item_cmpfunc.h:
  Auto merged
sql/item_func.cc:
  Auto merged
sql/item_func.h:
  Auto merged
sql/item_subselect.h:
  Auto merged
sql/item_sum.cc:
  Auto merged
sql/item_sum.h:
  Auto merged
sql/item_timefunc.cc:
  Auto merged
sql/my_decimal.cc:
  Auto merged
sql/my_decimal.h:
  Auto merged
sql/mysql_priv.h:
  Auto merged
sql/records.cc:
  Auto merged
sql/sql_base.cc:
  Auto merged
sql/sql_lex.h:
  Auto merged
sql/sql_select.cc:
  Auto merged
sql/sql_show.cc:
  Auto merged
sql/sql_table.cc:
  Auto merged
sql/sql_yacc.yy:
  Auto merged
sql-common/my_time.c:
  Auto merged
sql/table.cc:
  Auto merged
sql/table.h:
  Auto merged
mysql-test/r/type_newdecimal.result:
  SCCS merged
mysql-test/t/type_newdecimal.test:
  merging
sql/item.cc:
  merging
sql/item_subselect.cc:
  SCCS merged
sql/item_timefunc.h:
  merging
sql/sql_lex.cc:
  SCCS merged
sql/sql_select.h:
  merging

1 files changed, 26 insertions, 8 deletions

diff --git a/sql/item_sum.h b/sql/item_sum.h
index 3679780db60..13b6c2f00be 100644
--- a/sql/item_sum.h
+++ b/sql/item_sum.h
@@ -321,12 +321,23 @@ public:
 
 class Item_sum_num :public Item_sum
 {
+protected:
+  /*
+   val_xxx() functions may be called several times during the execution of a 
+   query. Derived classes that require extensive calculation in val_xxx()
+   maintain cache of aggregate value. This variable governs the validity of 
+   that cache.
+  */
+  bool is_evaluated;
 public:
-  Item_sum_num() :Item_sum() {}
-  Item_sum_num(Item *item_par) :Item_sum(item_par) {}
-  Item_sum_num(Item *a, Item* b) :Item_sum(a,b) {}
-  Item_sum_num(List<Item> &list) :Item_sum(list) {}
-  Item_sum_num(THD *thd, Item_sum_num *item) :Item_sum(thd, item) {}
+  Item_sum_num() :Item_sum(),is_evaluated(FALSE) {}
+  Item_sum_num(Item *item_par) 
+    :Item_sum(item_par), is_evaluated(FALSE) {}
+  Item_sum_num(Item *a, Item* b) :Item_sum(a,b),is_evaluated(FALSE) {}
+  Item_sum_num(List<Item> &list) 
+    :Item_sum(list), is_evaluated(FALSE) {}
+  Item_sum_num(THD *thd, Item_sum_num *item) 
+    :Item_sum(thd, item),is_evaluated(item->is_evaluated) {}
   bool fix_fields(THD *, Item **);
   longlong val_int()
   {
@@ -509,6 +520,12 @@ class Item_sum_count_distinct :public Item_sum_int
   */
   Unique *tree;
   /*
+   Storage for the value of count between calls to val_int() so val_int()
+   will not recalculate on each call. Validitiy of the value is stored in
+   is_evaluated.
+  */
+  longlong count;
+  /*
     Following is 0 normal object and pointer to original one for copy 
     (to correctly free resources)
   */
@@ -525,14 +542,15 @@ class Item_sum_count_distinct :public Item_sum_int
 public:
   Item_sum_count_distinct(List<Item> &list)
     :Item_sum_int(list), table(0), field_lengths(0), tmp_table_param(0),
-     force_copy_fields(0), tree(0), original(0), always_null(FALSE)
+     force_copy_fields(0), tree(0), count(0),
+     original(0), always_null(FALSE)
   { quick_group= 0; }
   Item_sum_count_distinct(THD *thd, Item_sum_count_distinct *item)
     :Item_sum_int(thd, item), table(item->table),
      field_lengths(item->field_lengths),
      tmp_table_param(item->tmp_table_param),
-     force_copy_fields(0), tree(item->tree), original(item),
-     tree_key_length(item->tree_key_length),
+     force_copy_fields(0), tree(item->tree), count(item->count), 
+     original(item), tree_key_length(item->tree_key_length),
      always_null(item->always_null)
   {}
   ~Item_sum_count_distinct();