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Fix LP BUG#682683

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Analysis:
The fix for LP BUG#680846 avoids evaluation of constant expressions
with subqueries in the GROUP/ORDER clauses in the procedure
remove_const(). The purpose of remove_const is to remove constant
expressions in the GROUP/ORDER clauses.
  
In order delay until execution the evaluation of such subqueries,
they were not removed in the GROUP/ORDER clause. As a result temp
table creation during execution attempted to create a column in the
temp table for each constant GROUP/ORDER expression. However, the
logic in create_tmp_table is to not create temp table columns for
constant items. The crash was due to a group Item without a
corresponding column in the temp table for GROUP BY.
  
Solution:
The patch adds back removal of constant expressions with subqueries.
In order for such expressions to be evaluated, so that the server can
ensure that such subquries return 1 row, the evaluation of these
expressions is delayed until execution.
This commit is contained in:
unknown
2010-12-02 21:54:40 +02:00
parent 1b3336dc30
commit 620aea4fde
4 changed files with 111 additions and 7 deletions
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10
sql/sql_select.h
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@ -1599,6 +1599,13 @@ public:
evaluated at optimization time.
*/
Item *exec_const_cond;
/*
Constant ORDER and/or GROUP expressions that contain subqueries. Such
expressions need to evaluated to verify that the subquery indeed
returns a single row. The evaluation of such expressions is delayed
until query execution.
*/
List<Item> exec_const_order_group_cond;
SQL_SELECT *select; ///<created in optimisation phase
JOIN_TAB *return_tab; ///<used only for outer joins
Item **ref_pointer_array; ///<used pointer reference for this select
@ -1762,7 +1769,8 @@ public:
bool send_row_on_empty_set()
{
return (do_send_rows && tmp_table_param.sum_func_count != 0 &&
!group_list && having_value != Item::COND_FALSE);
!(group_list || group_optimized_away) &&
having_value != Item::COND_FALSE);
}
bool change_result(select_result *result);
bool is_top_level_join() const