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bug#926 fix undone - it caused suboptimal execution plan for "range ON, no WHERE" query

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Another fix applied
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unknown
2003-09-05 11:42:21 +02:00
parent f0879fd9a7
commit ad66d486f0
1 changed files with 19 additions and 2 deletions
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21
sql/sql_select.cc
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@ -146,7 +146,7 @@ static void copy_sum_funcs(Item_sum **func_ptr);
static bool add_ref_to_table_cond(THD *thd, JOIN_TAB *join_tab);
static void init_sum_functions(Item_sum **func);
static bool update_sum_func(Item_sum **func);
static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
static void select_describe(JOIN *join, bool need_tmp_table,bool need_order,
bool distinct, const char *message=NullS);
static void describe_info(JOIN *join, const char *info);
@ -2663,13 +2663,30 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
join->thd->select_limit < join->best_positions[i].records_read &&
!(join->select_options & OPTION_FOUND_ROWS)))
{
/* Join with outer join condition */
COND *orig_cond=sel->cond;
sel->cond=and_conds(sel->cond,tab->on_expr);
if (sel->test_quick_select(tab->keys,
used_tables & ~ current_map,
(join->select_options &
OPTION_FOUND_ROWS ?
HA_POS_ERROR :
join->thd->select_limit)) < 0)
DBUG_RETURN(1); // Impossible range
{ /* before reporting "Impossible WHERE" for the whole query
we have to check isn't it only "impossible ON" instead */
sel->cond=orig_cond;
if (!tab->on_expr ||
sel->test_quick_select(tab->keys,
used_tables & ~ current_map,
(join->select_options &
OPTION_FOUND_ROWS ?
HA_POS_ERROR :
join->thd->select_limit)) < 0)
DBUG_RETURN(1); // Impossible WHERE
}
else
sel->cond=orig_cond;
/* Fix for EXPLAIN */
if (sel->quick)
join->best_positions[i].records_read= sel->quick->records;