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Fixed LP BUG#652727 and LP BUG#643424.

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The fixes for #643424 was part of the fix for #652727, that's why both
fixes are pushed together.

- The cause for #643424 was the improper use of get_partial_join_cost(),
  which assumed that the 'n_tables' parameter was the upper bound for
  query plan node indexes.
  Fixed by generalizing get_partial_join_cost() as a method that computes
  the cost of any partial join.

- The cause of #652727 was that JOIN::choose_subquery_plan() incorrectly
  deleted the contents of the old keyuse array in the cases when an injected
  plan would not provide more key accesses, and reoptimization was not actually
  performed.
This commit is contained in:
unknown
2010-11-02 15:27:01 +02:00
parent f670b6d22f
commit 9f2bddbd80
5 changed files with 188 additions and 67 deletions
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16
sql/sql_select.h
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@ -1374,9 +1374,16 @@ private:
JOIN& operator=(const JOIN &rhs); /**< not implemented */
protected:
/* Results of reoptimizing a JOIN via JOIN::reoptimize(). */
enum enum_reopt_result {
REOPT_NEW_PLAN, /* there is a new reoptimized plan */
REOPT_OLD_PLAN, /* no new improved plan can be found, use the old one */
REOPT_ERROR, /* an irrecovarable error occured during reoptimization */
REOPT_NONE /* not yet reoptimized */
};
/* Support for plan reoptimization with rewritten conditions. */
int reoptimize(Item *added_where, table_map join_tables,
POSITION *save_best_positions);
enum_reopt_result reoptimize(Item *added_where, table_map join_tables);
int save_query_plan(DYNAMIC_ARRAY *save_keyuse, POSITION *save_positions,
KEYUSE **save_join_tab_keyuse,
key_map *save_join_tab_checked_keys);
@ -1762,6 +1769,9 @@ public:
}
bool setup_subquery_caches();
bool choose_subquery_plan(table_map join_tables);
void get_partial_join_cost(uint n_tables,
double *read_time_arg, double *record_count_arg);
private:
/**
TRUE if the query contains an aggregate function but has no GROUP
@ -1993,8 +2003,6 @@ inline Item * and_items(Item* cond, Item *item)
return (cond? (new Item_cond_and(cond, item)) : item);
}
bool choose_plan(JOIN *join,table_map join_tables);
void get_partial_join_cost(JOIN *join, uint n_tables, double *read_time_arg,
double *record_count_arg);
void optimize_wo_join_buffering(JOIN *join, uint first_tab, uint last_tab,
table_map last_remaining_tables,
bool first_alt, uint no_jbuf_before,