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new IN subquery engine added for simple IN with non-primary index but without NULL returning

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(SCRUM) (part of WL#818)
This commit is contained in:
bell@sanja.is.com.ua
2003-07-08 00:08:00 +03:00
parent acece34bce
commit 8279740af4
6 changed files with 174 additions and 47 deletions
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84
sql/sql_select.cc
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@ -32,7 +32,7 @@
const char *join_type_str[]={ "UNKNOWN","system","const","eq_ref","ref",
"MAYBE_REF","ALL","range","index","fulltext",
"ref_or_null","simple_in"
"ref_or_null","simple_in","index_in"
};
static void optimize_keyuse(JOIN *join, DYNAMIC_ARRAY *keyuse_array);
@ -440,6 +440,42 @@ err:
DBUG_RETURN(-1); /* purecov: inspected */
}
/*
test if it is known for optimisation IN subquery
SYNOPSYS
JOIN::test_in_subselect
where - pointer for variable in which conditions should be
stored if subquery is known
RETURN
1 - known
0 - unknown
*/
bool JOIN::test_in_subselect(Item **where)
{
if (conds->type() == Item::FUNC_ITEM &&
((class Item_func *)this->conds)->functype() == Item_func::EQ_FUNC &&
((Item_func *)conds)->arguments()[0]->type() == Item::REF_ITEM &&
((Item_func *)conds)->arguments()[1]->type() == Item::FIELD_ITEM)
{
join_tab->info= "Using index";
*where= 0;
return 1;
}
if (conds->type() == Item::COND_ITEM &&
((class Item_func *)this->conds)->functype() ==
Item_func::COND_AND_FUNC)
{
*where= conds;
join_tab->info= "Using index; Using where";
return 1;
}
return 0;
}
/*
global select optimisation.
return 0 - success
@ -729,37 +765,33 @@ JOIN::optimize()
*/
if (!group_list && !order && !having &&
unit->item && unit->item->substype() == Item_subselect::IN_SUBS &&
tables == 1 && join_tab[0].type == JT_EQ_REF &&
conds &&
tables == 1 && conds &&
!unit->first_select()->next_select())
{
Item *where= 0;
bool ok= 0;
if (conds->type() == Item::FUNC_ITEM &&
((class Item_func *)this->conds)->functype() == Item_func::EQ_FUNC &&
((Item_func *)conds)->arguments()[0]->type() == Item::REF_ITEM &&
((Item_func *)conds)->arguments()[1]->type() == Item::FIELD_ITEM)
if (join_tab[0].type == JT_EQ_REF)
{
ok= 1;
join_tab->info= "Using index";
if (test_in_subselect(&where))
{
join_tab[0].type= JT_SIMPLE_IN;
error= 0;
DBUG_RETURN(unit->item->
change_engine(new subselect_simplein_engine(thd, join_tab,
unit->item,
where)));
}
}
else if (conds->type() == Item::COND_ITEM &&
((class Item_func *)this->conds)->functype() ==
Item_func::COND_AND_FUNC)
else if (join_tab[0].type == JT_REF)
{
ok= 1;
where= conds;
join_tab->info= "Using index; Using where";
}
if (ok)
{
join_tab[0].type= JT_SIMPLE_IN;
error= 0;
DBUG_RETURN(unit->item->
change_engine(new subselect_simplein_engine(thd, join_tab,
unit->item,
where)));
if (test_in_subselect(&where))
{
join_tab[0].type= JT_INDEX_IN;
error= 0;
DBUG_RETURN(unit->item->
change_engine(new subselect_indexin_engine(thd, join_tab,
unit->item,
where)));
}
}
}