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MWL#89

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Merge MWL#89 with 5.3.
This commit is contained in:
unknown 2011-03-01 14:16:28 +02:00
commit 7895c35874
71 changed files with 8676 additions and 1548 deletions
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36
sql/opt_range.cc
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@ -11102,7 +11102,7 @@ static bool get_constant_key_infix(KEY *index_info, SEL_ARG *index_range_tree,
uchar *key_infix, uint *key_infix_len,
KEY_PART_INFO **first_non_infix_part);
static bool
check_group_min_max_predicates(COND *cond, Item_field *min_max_arg_item,
check_group_min_max_predicates(Item *cond, Item_field *min_max_arg_item,
Field::imagetype image_type);
static void
@ -11676,13 +11676,16 @@ get_best_group_min_max(PARAM *param, SEL_TREE *tree)
*/
static bool
check_group_min_max_predicates(COND *cond, Item_field *min_max_arg_item,
check_group_min_max_predicates(Item *cond, Item_field *min_max_arg_item,
Field::imagetype image_type)
{
DBUG_ENTER("check_group_min_max_predicates");
DBUG_ASSERT(cond && min_max_arg_item);
cond= cond->real_item();
if (cond->get_cached_item())
cond= cond->get_cached_item();
Item::Type cond_type= cond->type();
if (cond_type == Item::COND_ITEM) /* 'AND' or 'OR' */
{
@ -11699,18 +11702,25 @@ check_group_min_max_predicates(COND *cond, Item_field *min_max_arg_item,
}
/*
TODO:
This is a very crude fix to handle sub-selects in the WHERE clause
(Item_subselect objects). With the test below we rule out from the
optimization all queries with subselects in the WHERE clause. What has to
be done, is that here we should analyze whether the subselect references
the MIN/MAX argument field, and disallow the optimization only if this is
so.
Disallow loose index scan if the MIN/MAX argument field is referenced by
a subquery in the WHERE clause.
*/
if (cond_type == Item::SUBSELECT_ITEM ||
(cond->get_cached_item() &&
cond->get_cached_item()->type() == Item::SUBSELECT_ITEM))
DBUG_RETURN(FALSE);
if (cond_type == Item::SUBSELECT_ITEM)
{
Item_subselect *subs_cond= (Item_subselect*) cond;
if (subs_cond->is_correlated)
{
DBUG_ASSERT(subs_cond->depends_on.elements > 0);
List_iterator_fast<Item*> li(subs_cond->depends_on);
Item **dep;
while ((dep= li++))
{
if ((*dep)->eq(min_max_arg_item, FALSE))
DBUG_RETURN(FALSE);
}
}
DBUG_RETURN(TRUE);
}
/*
Condition of the form 'field' is equivalent to 'field <> 0' and thus