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independent ALL/ANY subselect on top of WHERE clause (subselect without GROUP BY or aggregate functions) optimisation

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(SCRUM) (WL#1086)


mysql-test/r/subselect.result:
  new optimisation tests
mysql-test/t/subselect.test:
  new optimisation tests
sql/item_cmpfunc.cc:
  new NOT
sql/item_cmpfunc.h:
  new NOT
sql/item_subselect.cc:
  independent ALL/ANY in top of WHERE clause optimisation
sql/item_subselect.h:
  independent ALL/ANY in top of WHERE clause optimisation
sql/item_sum.cc:
  prevent fixlields call for parameters of min/max if it is already done
sql/sql_union.cc:
  removed debuging print
sql/sql_yacc.yy:
  support of ALL optimisation
This commit is contained in:
unknown
2003-07-24 15:26:21 +03:00
parent d35bf560be
commit 9a3979e234
9 changed files with 130 additions and 21 deletions
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77
sql/item_subselect.cc
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@ -357,7 +357,7 @@ bool Item_in_subselect::test_limit(SELECT_LEX_UNIT *unit)
Item_in_subselect::Item_in_subselect(THD *thd, Item * left_exp,
st_select_lex *select_lex):
Item_exists_subselect()
Item_exists_subselect(), upper_not(0)
{
DBUG_ENTER("Item_in_subselect::Item_in_subselect");
left_expr= left_exp;
@ -373,8 +373,8 @@ Item_in_subselect::Item_in_subselect(THD *thd, Item * left_exp,
Item_allany_subselect::Item_allany_subselect(THD *thd, Item * left_exp,
compare_func_creator fn,
st_select_lex *select_lex):
Item_in_subselect()
st_select_lex *select_lex)
:Item_in_subselect()
{
DBUG_ENTER("Item_in_subselect::Item_in_subselect");
left_expr= left_exp;
@ -471,17 +471,16 @@ String *Item_in_subselect::val_str(String *str)
}
Item_in_subselect::Item_in_subselect(Item_in_subselect *item):
Item_exists_subselect(item)
Item_exists_subselect(item), upper_not(item->upper_not)
{
left_expr= item->left_expr;
abort_on_null= item->abort_on_null;
}
Item_allany_subselect::Item_allany_subselect(Item_allany_subselect *item):
Item_in_subselect(item)
{
func= item->func;
}
Item_allany_subselect::Item_allany_subselect(Item_allany_subselect *item)
:Item_in_subselect(item),
func(item->func)
{}
Item_subselect::trans_res
Item_in_subselect::single_value_transformer(JOIN *join,
@ -495,6 +494,57 @@ Item_in_subselect::single_value_transformer(JOIN *join,
THD *thd= join->thd;
thd->where= "scalar IN/ALL/ANY subquery";
if ((abort_on_null || (upper_not && upper_not->top_level())) &&
!select_lex->master_unit()->dependent &&
(func == &Item_bool_func2::gt_creator ||
func == &Item_bool_func2::lt_creator ||
func == &Item_bool_func2::ge_creator ||
func == &Item_bool_func2::le_creator) &&
!select_lex->group_list.elements &&
!select_lex->with_sum_func)
{
Item *item;
subs_type type= substype();
if (func == &Item_bool_func2::le_creator ||
func == &Item_bool_func2::lt_creator)
{
/*
(ALL && (> || =>)) || (ANY && (< || =<))
for ALL condition is inverted
*/
item= new Item_sum_max(*select_lex->ref_pointer_array);
}
else
{
/*
(ALL && (< || =<)) || (ANY && (> || =>))
for ALL condition is inverted
*/
item= new Item_sum_min(*select_lex->ref_pointer_array);
}
*select_lex->ref_pointer_array= item;
select_lex->item_list.empty();
select_lex->item_list.push_back(item);
if (item->fix_fields(thd, join->tables_list, &item))
{
DBUG_RETURN(ERROR);
}
// left expression belong to outer select
SELECT_LEX *current= thd->lex.current_select, *up;
thd->lex.current_select= up= current->return_after_parsing();
if (left_expr->fix_fields(thd, up->get_table_list(), 0))
{
thd->lex.current_select= current;
DBUG_RETURN(ERROR);
}
thd->lex.current_select= current;
substitution= (*func)(left_expr,
new Item_singlerow_subselect(thd, select_lex));
DBUG_RETURN(OK);
}
if (!substitution)
{
//first call for this unit
@ -736,10 +786,11 @@ Item_allany_subselect::select_transformer(JOIN *join)
return single_value_transformer(join, left_expr, func);
}
subselect_single_select_engine::subselect_single_select_engine(THD *thd,
st_select_lex *select,
select_subselect *result,
Item_subselect *item):
subselect_single_select_engine::
subselect_single_select_engine(THD *thd,
st_select_lex *select,
select_subselect *result,
Item_subselect *item):
subselect_engine(thd, item, result),
prepared(0), optimized(0), executed(0)
{