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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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30
mysql-test/r/subselect.result
View File

@ -1245,7 +1245,7 @@ id select_type table type possible_keys key key_len ref rows Extra
2 DEPENDENT SUBQUERY t1 eq_ref PRIMARY PRIMARY 4 func 1 Using where
2 DEPENDENT SUBQUERY t3 eq_ref PRIMARY PRIMARY 4 test.t1.b 1 Using where; Using index
drop table t1, t2, t3;
create table t1 (a int, b int, index a (a));
create table t1 (a int, b int, index a (a,b));
create table t2 (a int, index a (a));
create table t3 (a int, b int, index a (a));
insert into t1 values (1,10), (2,20), (3,30), (4,40);
@ -1259,7 +1259,15 @@ a
explain select * from t2 where t2.a in (select a from t1);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 index NULL a 5 NULL 4 Using where; Using index
2 DEPENDENT SUBQUERY t1 ref a a 5 func 10 Using where; Using index
2 DEPENDENT SUBQUERY t1 index_in a a 5 func 100 Using index
select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
a
2
4
explain select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 index NULL a 5 NULL 4 Using where; Using index
2 DEPENDENT SUBQUERY t1 index_in a a 5 func 100 Using index; Using where
select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
a
2
@ -1267,8 +1275,22 @@ a
explain select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 index NULL a 5 NULL 4 Using where; Using index
2 DEPENDENT SUBQUERY t1 ref a a 5 func 10 Using where
2 DEPENDENT SUBQUERY t3 index a a 5 NULL 3 Using where; Using index
2 DEPENDENT SUBQUERY t3 index a a 5 NULL 3 Using index
2 DEPENDENT SUBQUERY t1 ref a a 10 func,test.t3.a 100 Using where; Using index
insert into t1 values (3,31);
select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
a
2
3
4
select * from t2 where t2.a in (select a from t1 where t1.b <> 30 and t1.b <> 31);
a
2
4
explain select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 index NULL a 5 NULL 4 Using where; Using index
2 DEPENDENT SUBQUERY t1 index_in a a 5 func 100 Using index; Using where
drop table t1, t2, t3;
create table t1 (a int, b int);
create table t2 (a int, b int);

8
mysql-test/t/subselect.test
View File

@ -824,7 +824,7 @@ explain select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
explain select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
drop table t1, t2, t3;
create table t1 (a int, b int, index a (a));
create table t1 (a int, b int, index a (a,b));
create table t2 (a int, index a (a));
create table t3 (a int, b int, index a (a));
insert into t1 values (1,10), (2,20), (3,30), (4,40);
@ -841,8 +841,14 @@ insert into t2 values (2), (3), (4), (5);
insert into t3 values (10,3), (20,4), (30,5);
select * from t2 where t2.a in (select a from t1);
explain select * from t2 where t2.a in (select a from t1);
select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
explain select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
explain select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
insert into t1 values (3,31);
select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
select * from t2 where t2.a in (select a from t1 where t1.b <> 30 and t1.b <> 31);
explain select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
drop table t1, t2, t3;
#
# alloc_group_fields() working

59
sql/item_subselect.cc
View File

@ -972,8 +972,13 @@ int subselect_simplein_engine::exec()
((Item_in_subselect *) item)->value= (!cond || cond->val_int()?1:0);
}
}
{
int tmp= 0;
DBUG_RETURN(end_exec(table) || (error != 0));
}
int subselect_simplein_engine::end_exec(TABLE *table)
{
DBUG_ENTER("subselect_simplein_engine::end_exec");
int error=0, tmp;
if ((tmp= table->file->extra(HA_EXTRA_NO_CACHE)))
{
DBUG_PRINT("error", ("extra(HA_EXTRA_NO_CACHE) failed"));
@ -986,8 +991,56 @@ int subselect_simplein_engine::exec()
}
if (error == 1)
table->file->print_error(tmp, MYF(0));
DBUG_RETURN(error != 0);
}
int subselect_indexin_engine::exec()
{
DBUG_ENTER("subselect_indexin_engine::exec");
int error;
TABLE *table= tab->table;
((Item_in_subselect *) item)->value= 0;
if ((tab->ref.key_err= (*tab->ref.key_copy)->copy()))
{
table->status= STATUS_NOT_FOUND;
error= -1;
}
DBUG_RETURN(error != 0)
else
{
error= table->file->index_read(table->record[0],
tab->ref.key_buff,
tab->ref.key_length,HA_READ_KEY_EXACT);
if (error && error != HA_ERR_KEY_NOT_FOUND)
error= report_error(table, error);
else
{
for(;;)
{
error= 0;
table->null_row= 0;
if (!table->status)
{
if (!cond || cond->val_int())
{
((Item_in_subselect *) item)->value= 1;
goto finish;
}
}
else
goto finish;
error= table->file->index_next_same(table->record[0],
tab->ref.key_buff,
tab->ref.key_length);
if (error && error != HA_ERR_KEY_NOT_FOUND)
{
error= report_error(table, error);
goto finish;
}
}
}
}
finish:
DBUG_RETURN(end_exec(table) || (error != 0));
}
uint subselect_single_select_engine::cols()

13
sql/item_subselect.h
View File

@ -184,6 +184,7 @@ public:
friend class select_exists_subselect;
friend class subselect_simplein_engine;
friend class subselect_indexin_engine;
};
/* IN subselect */
@ -314,6 +315,7 @@ public:
struct st_join_table;
class subselect_simplein_engine: public subselect_engine
{
protected:
st_join_table *tab;
Item *cond;
public:
@ -330,4 +332,15 @@ public:
bool dependent() { return 1; }
bool uncacheable() { return 1; }
void exclude();
static int end_exec(TABLE *table);
};
class subselect_indexin_engine: public subselect_simplein_engine
{
public:
subselect_indexin_engine(THD *thd, st_join_table *tab_arg,
Item_subselect *subs, Item *where)
:subselect_simplein_engine(thd, tab_arg, subs, where)
{}
int exec();
};

74
sql/sql_select.cc
View File

@ -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
@ -729,30 +765,13 @@ 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";
}
else if (conds->type() == Item::COND_ITEM &&
((class Item_func *)this->conds)->functype() ==
Item_func::COND_AND_FUNC)
{
ok= 1;
where= conds;
join_tab->info= "Using index; Using where";
}
if (ok)
if (test_in_subselect(&where))
{
join_tab[0].type= JT_SIMPLE_IN;
error= 0;
@ -762,6 +781,19 @@ JOIN::optimize()
where)));
}
}
else if (join_tab[0].type == JT_REF)
{
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)));
}
}
}
/*
Need to tell Innobase that to play it safe, it should fetch all

5
sql/sql_select.h
View File

@ -76,7 +76,7 @@ typedef struct st_join_cache {
enum join_type { JT_UNKNOWN,JT_SYSTEM,JT_CONST,JT_EQ_REF,JT_REF,JT_MAYBE_REF,
JT_ALL, JT_RANGE, JT_NEXT, JT_FT, JT_REF_OR_NULL,
JT_SIMPLE_IN};
JT_SIMPLE_IN, JT_INDEX_IN};
class JOIN;
@ -277,7 +277,8 @@ class JOIN :public Sql_alloc
bool rollup_init();
bool rollup_make_fields(List<Item> &all_fields, List<Item> &fields,
Item_sum ***func);
int JOIN::rollup_send_data(uint idx);
int rollup_send_data(uint idx);
bool test_in_subselect(Item **where);
};