diff options
Diffstat (limited to 'sql/item_sum.h')
| -rw-r--r-- | sql/item_sum.h | 34 |
1 files changed, 26 insertions, 8 deletions
diff --git a/sql/item_sum.h b/sql/item_sum.h index f1ea95214de..a2b2f7cab92 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(); |