Commit 1f739ca4 authored by unknown's avatar unknown

make JOIN::prepare, JOIN::optimize only once for EXPLAIN of derived table

(BUG#2120 sfter merge)


mysql-test/r/derived.result:
  correct results of derived tble EXPLAIN
  test of "Using Index" with derived tables
mysql-test/t/derived.test:
  test of "Using Index" with derived tables
sql/mysql_priv.h:
  way to force derived table save JOIN after execution
sql/sql_derived.cc:
  way to force derived table save JOIN after execution
sql/sql_lex.h:
  way to force derived table save JOIN after execution
sql/sql_select.cc:
  make JOIN::prepare, JOIN::optimize only once for EXPLAIN of derived table
parent 00b2168b
......@@ -141,7 +141,7 @@ a t
explain select count(*) from t1 as tt1, (select * from t1) as tt2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
2 DERIVED t1 index NULL a 4 NULL 10000 Using index
2 DERIVED t1 ALL NULL NULL NULL NULL 10000
drop table t1;
SELECT * FROM (SELECT (SELECT * FROM (SELECT 1 as a) as a )) as b;
(SELECT * FROM (SELECT 1 as a) as a )
......@@ -189,13 +189,13 @@ id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY m2 ALL NULL NULL NULL NULL 9
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 6 Using where
2 DERIVED mp ALL NULL NULL NULL NULL 9 Using temporary; Using filesort
2 DERIVED m1 index NULL PRIMARY 3 NULL 9 Using index
2 DERIVED m1 eq_ref PRIMARY PRIMARY 3 test.mp.mat_id 1
explain SELECT STRAIGHT_JOIN d.pla_id, m2.test FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY m2 ALL NULL NULL NULL NULL 9
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 6 Using where
2 DERIVED mp ALL NULL NULL NULL NULL 9 Using temporary; Using filesort
2 DERIVED m1 index NULL PRIMARY 3 NULL 9 Using index
2 DERIVED m1 eq_ref PRIMARY PRIMARY 3 test.mp.mat_id 1
drop table t1,t2;
SELECT a.x FROM (SELECT 1 AS x) AS a HAVING a.x = 1;
x
......@@ -229,8 +229,8 @@ explain select count(*) from t1 INNER JOIN (SELECT A.E1, A.E2, A.E3 FROM t1 AS A
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 THEMAX.E2 1 Using where
2 DERIVED A index NULL PRIMARY 4 NULL 2 Using where; Using index
3 DEPENDENT SUBQUERY B index NULL PRIMARY 4 NULL 2 Using where; Using index
2 DERIVED A ALL NULL NULL NULL NULL 2 Using where
3 DEPENDENT SUBQUERY B ALL NULL NULL NULL NULL 2 Using where
drop table t1;
create table t1 (a int);
insert into t1 values (1),(2);
......@@ -309,3 +309,14 @@ id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 3 Using temporary; Using filesort
2 DERIVED x ALL NULL NULL NULL NULL 17 Using temporary; Using filesort
2 DERIVED y ALL NULL NULL NULL NULL 17 Using where
drop table t1;
create table t2 (a int, b int, primary key (a));
insert into t2 values (1,7),(2,7);
explain select a from t2 where a>1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range PRIMARY PRIMARY 4 NULL 2 Using where; Using index
explain select a from (select a from t2 where a>1) tt;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> system NULL NULL NULL NULL 1
2 DERIVED t2 range PRIMARY PRIMARY 4 NULL 2 Using where; Using index
drop table t2;
......@@ -192,3 +192,13 @@ CREATE TABLE t1 (name char(1) default NULL, val int(5) default NULL);
INSERT INTO t1 VALUES ('a',1), ('a',2), ('a',2), ('a',2), ('a',3), ('a',6), ('a',7), ('a',11), ('a',11), ('a',12), ('a',13), ('a',13), ('a',20), ('b',2), ('b',3), ('b',4), ('b',5);
SELECT s.name, AVG(s.val) AS median FROM (SELECT x.name, x.val FROM t1 x, t1 y WHERE x.name=y.name GROUP BY x.name, x.val HAVING SUM(y.val <= x.val) >= COUNT(*)/2 AND SUM(y.val >= x.val) >= COUNT(*)/2) AS s GROUP BY s.name;
explain SELECT s.name, AVG(s.val) AS median FROM (SELECT x.name, x.val FROM t1 x, t1 y WHERE x.name=y.name GROUP BY x.name, x.val HAVING SUM(y.val <= x.val) >= COUNT(*)/2 AND SUM(y.val >= x.val) >= COUNT(*)/2) AS s GROUP BY s.name;
drop table t1;
#
# "Using index" in explain
#
create table t2 (a int, b int, primary key (a));
insert into t2 values (1,7),(2,7);
explain select a from t2 where a>1;
explain select a from (select a from t2 where a>1) tt;
drop table t2;
......@@ -247,7 +247,9 @@ extern CHARSET_INFO *national_charset_info, *table_alias_charset;
// uncachable cause
#define UNCACHEABLE_DEPENDENT 1
#define UNCACHEABLE_RAND 2
#define UNCACHEABLE_SIDEEFFECT 4
#define UNCACHEABLE_SIDEEFFECT 4
// forcing to save JOIN for explain
#define UNCACHEABLE_EXPLAIN 8
#ifdef EXTRA_DEBUG
/*
......
......@@ -62,6 +62,15 @@ mysql_handle_derived(LEX *lex)
return 1;
}
}
if (lex->describe)
{
/*
Force join->join_tmp creation, because we will use this JOIN
twice for EXPLAIN and we have to have unchanged join for EXPLAINing
*/
sl->uncacheable|= UNCACHEABLE_EXPLAIN;
sl->master_unit()->uncacheable|= UNCACHEABLE_EXPLAIN;
}
}
}
return 0;
......
......@@ -232,6 +232,7 @@ public:
UNCACHEABLE_DEPENDENT
UNCACHEABLE_RAND
UNCACHEABLE_SIDEEFFECT
UNCACHEABLE_EXPLAIN
*/
uint8 uncacheable;
enum sub_select_type linkage;
......
......@@ -1579,8 +1579,8 @@ mysql_select(THD *thd, Item ***rref_pointer_array,
goto err;
}
}
free_join= 0;
}
free_join= 0;
join->select_options= select_options;
}
else
......@@ -3769,11 +3769,6 @@ JOIN::join_free(bool full)
{
if (tab->table)
{
if (tab->table->key_read)
{
tab->table->key_read= 0;
tab->table->file->extra(HA_EXTRA_NO_KEYREAD);
}
/* Don't free index if we are using read_record */
if (!tab->read_record.table)
tab->table->file->index_end();
......@@ -9128,6 +9123,9 @@ int mysql_explain_union(THD *thd, SELECT_LEX_UNIT *unit, select_result *result)
sl;
sl= sl->next_select())
{
// drop UNCACHEABLE_EXPLAIN, because it is for internal usage only
uint8 uncacheable= (sl->uncacheable & ~UNCACHEABLE_EXPLAIN);
res= mysql_explain_select(thd, sl,
(((&thd->lex->select_lex)==sl)?
((thd->lex->all_selects_list != sl) ?
......@@ -9135,13 +9133,13 @@ int mysql_explain_union(THD *thd, SELECT_LEX_UNIT *unit, select_result *result)
((sl == first)?
((sl->linkage == DERIVED_TABLE_TYPE) ?
"DERIVED":
((sl->uncacheable & UNCACHEABLE_DEPENDENT) ?
((uncacheable & UNCACHEABLE_DEPENDENT) ?
"DEPENDENT SUBQUERY":
(sl->uncacheable?"UNCACHEABLE SUBQUERY":
(uncacheable?"UNCACHEABLE SUBQUERY":
"SUBQUERY"))):
((sl->uncacheable & UNCACHEABLE_DEPENDENT) ?
((uncacheable & UNCACHEABLE_DEPENDENT) ?
"DEPENDENT UNION":
sl->uncacheable?"UNCACHEABLE UNION":
uncacheable?"UNCACHEABLE UNION":
"UNION"))),
result);
if (res)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment