new EXPLAIN

fixed bug in mysql-test/create-test-result
fixed bug in union-subselect engine

mysql-test/create-test-result

@@ -27,6 +27,7 @@ test_name=$1
 [ -z $test_name ] && usage
 
 result_file=$RESULT_DIR/$test_name.result
+reject_file=$RESULT_DIR/$test_name.reject
 
 [ -f $result_file ] && die "result file $result_file  has already been created"
 
@@ -34,8 +35,6 @@ touch $result_file
 echo "Running the test case against empty file, will fail, but don't worry"
 ./mysql-test-run --local $test_name
 
-reject_file=$result_file.reject
-
 if [ -f $reject_file ] ; then
   echo "Below are the contents of the reject file:"
   echo "-----start---------------------"

mysql-test/r/compare.result

@@ -2,8 +2,8 @@ drop table if exists t1;
 CREATE TABLE t1 (id CHAR(12) not null, PRIMARY KEY (id));
 insert into t1 values ('000000000001'),('000000000002');
 explain select * from t1 where id=000000000001;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	PRIMARY	PRIMARY	12	NULL	2	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	PRIMARY	PRIMARY	12	NULL	2	where used; Using index
 select * from t1 where id=000000000001;
 id
 000000000001

mysql-test/r/create.result

@@ -62,8 +62,8 @@ create table t1 (a int auto_increment not null primary key, B CHAR(20));
 insert into t1 (b) values ("hello"),("my"),("world");
 create table t2 (key (b)) select * from t1;
 explain select * from t2 where b="world";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	ref	B	B	21	const	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	ref	B	B	21	const	1	where used
 select * from t2 where b="world";
 a	B
 3	world

mysql-test/r/distinct.result

@@ -172,10 +172,10 @@ b
 INSERT INTO t2 values (1),(2),(3);
 INSERT INTO t3 VALUES (1,'1'),(2,'2'),(1,'1'),(2,'2');
 explain SELECT distinct t3.a FROM t3,t2,t1 WHERE t3.a=t1.b AND t1.a=t2.a;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t3	index	a	a	5	NULL	6	Using index; Using temporary
-t2	index	a	a	4	NULL	5	Using index; Distinct
-t1	eq_ref	PRIMARY	PRIMARY	4	t2.a	1	where used; Distinct
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t3	index	a	a	5	NULL	6	Using index; Using temporary
+1	FIRST	t2	index	a	a	4	NULL	5	Using index; Distinct
+1	FIRST	t1	eq_ref	PRIMARY	PRIMARY	4	t2.a	1	where used; Distinct
 SELECT distinct t3.a FROM t3,t2,t1 WHERE t3.a=t1.b AND t1.a=t2.a;
 a
 1
@@ -188,9 +188,9 @@ insert into t3 select * from t4;
 insert into t4 select * from t3;
 insert into t3 select * from t4;
 explain select distinct t1.a from t1,t3 where t1.a=t3.a;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	PRIMARY	PRIMARY	4	NULL	2	Using index; Using temporary
-t3	ref	a	a	5	t1.a	10	Using index; Distinct
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	PRIMARY	PRIMARY	4	NULL	2	Using index; Using temporary
+1	FIRST	t3	ref	a	a	5	t1.a	10	Using index; Distinct
 select distinct t1.a from t1,t3 where t1.a=t3.a;
 a
 1
@@ -274,14 +274,14 @@ on j_lj_t3.id=t3_lj.id
 WHERE
 ((t1.id=j_lj_t2.id AND t2_lj.id IS NULL) OR (t1.id=t2.id AND t2.idx=2))
 AND ((t1.id=j_lj_t3.id AND t3_lj.id IS NULL) OR (t1.id=t3.id AND t3.idx=2));
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	id	id	4	NULL	2	Using index; Using temporary
-t2	index	id	id	8	NULL	1	Using index; Distinct
-t3	index	id	id	8	NULL	1	Using index; Distinct
-j_lj_t2	index	id	id	4	NULL	2	where used; Using index; Distinct
-t2_lj	index	id	id	8	NULL	1	where used; Using index; Distinct
-j_lj_t3	index	id	id	4	NULL	2	where used; Using index; Distinct
-t3_lj	index	id	id	8	NULL	1	where used; Using index; Distinct
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	id	id	4	NULL	2	Using index; Using temporary
+1	FIRST	t2	index	id	id	8	NULL	1	Using index; Distinct
+1	FIRST	t3	index	id	id	8	NULL	1	Using index; Distinct
+1	FIRST	j_lj_t2	index	id	id	4	NULL	2	where used; Using index; Distinct
+1	FIRST	t2_lj	index	id	id	8	NULL	1	where used; Using index; Distinct
+1	FIRST	j_lj_t3	index	id	id	4	NULL	2	where used; Using index; Distinct
+1	FIRST	t3_lj	index	id	id	8	NULL	1	where used; Using index; Distinct
 SELECT DISTINCT
 t1.id
 from

mysql-test/r/explain.result

@@ -9,22 +9,22 @@ select * from t1 where str="foo";
 id	str
 3	foo
 explain select * from t1 where str is null;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	str	str	11	const	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	str	str	11	const	1	where used
 explain select * from t1 where str="foo";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	const	str	str	11	const	1	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	const	str	str	11	const	1	
 explain select * from t1 ignore key (str) where str="foo";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	4	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	4	where used
 explain select * from t1 use key (str,str) where str="foo";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	const	str	str	11	const	1	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	const	str	str	11	const	1	
 explain select * from t1 use key (str,str,foo) where str="foo";
 Key column 'foo' doesn't exist in table
 explain select * from t1 ignore key (str,str,foo) where str="foo";
 Key column 'foo' doesn't exist in table
 drop table t1;
 explain select 1;
-Comment
-No tables used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST								No tables used

mysql-test/r/group_by.result

@@ -225,19 +225,19 @@ key (score)
 );
 INSERT INTO t1 VALUES (1,1,1),(2,2,2),(2,1,1),(3,3,3),(4,3,3),(5,3,3);
 explain select userid,count(*) from t1 group by userid desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	6	Using temporary; Using filesort
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	6	Using temporary; Using filesort
 select userid,count(*) from t1 group by userid desc;
 userid	count(*)
 3	3
 2	1
 1	2
 explain select spid,count(*) from t1 where spid between 1 and 2 group by spid desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	spID	spID	5	NULL	2	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	spID	spID	5	NULL	2	where used; Using index
 explain select spid,count(*) from t1 where spid between 1 and 2 group by spid;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	spID	spID	5	NULL	2	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	spID	spID	5	NULL	2	where used; Using index
 select spid,count(*) from t1 where spid between 1 and 2 group by spid;
 spid	count(*)
 1	1
@@ -247,8 +247,8 @@ spid	count(*)
 2	2
 1	1
 explain select sql_big_result spid,sum(userid) from t1 group by spid desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	6	Using filesort
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	6	Using filesort
 select sql_big_result spid,sum(userid) from t1 group by spid desc;
 spid	sum(userid)
 5	3
@@ -257,8 +257,8 @@ spid	sum(userid)
 2	3
 1	1
 explain select sql_big_result score,count(*) from t1 group by score desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	NULL	score	3	NULL	6	Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	NULL	score	3	NULL	6	Using index
 select sql_big_result score,count(*) from t1 group by score desc;
 score	count(*)
 3	3

mysql-test/r/heap.result

@@ -65,8 +65,8 @@ a
 869751
 alter table t1 type=myisam;
 explain select * from t1 where a in (869751,736494,226312,802616);
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	uniq_id	uniq_id	4	NULL	4	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	uniq_id	uniq_id	4	NULL	4	where used; Using index
 drop table t1;
 create table t1 (x int not null, y int not null, key x (x), unique y (y))
 type=heap;
@@ -84,9 +84,9 @@ x	y	x	y
 2	5	2	2
 2	6	2	2
 explain select * from t1,t1 as t2 where t1.x=t2.y;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	x	NULL	NULL	NULL	6	
-t2	eq_ref	y	y	4	t1.x	1	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	x	NULL	NULL	NULL	6	
+1	FIRST	t2	eq_ref	y	y	4	t1.x	1	
 drop table t1;
 create table t1 (a int) type=heap;
 insert into t1 values(1);
@@ -158,18 +158,18 @@ drop table t1;
 create table t1 (btn char(10) not null, key(btn)) type=heap;
 insert into t1 values ("hello"),("hello"),("hello"),("hello"),("hello"),("a"),("b"),("c"),("d"),("e"),("f"),("g"),("h"),("i");
 explain select * from t1 where btn like "q%";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	btn	NULL	NULL	NULL	14	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	btn	NULL	NULL	NULL	14	where used
 select * from t1 where btn like "q%";
 btn
 alter table t1 add column new_col char(1) not null, add key (btn,new_col), drop key btn;
 update t1 set new_col=btn;
 explain select * from t1 where btn="a";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	btn	NULL	NULL	NULL	14	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	btn	NULL	NULL	NULL	14	where used
 explain select * from t1 where btn="a" and new_col="a";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	btn	btn	11	const,const	10	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	btn	btn	11	const,const	10	where used
 drop table t1;
 CREATE TABLE t1 (
 a int default NULL,
@@ -181,16 +181,16 @@ INSERT INTO t1 VALUES (NULL,99),(99,NULL),(1,1),(2,2),(1,3);
 SELECT * FROM t1 WHERE a=NULL;
 a	b
 explain SELECT * FROM t1 WHERE a IS NULL;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a	a	5	const	10	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a	a	5	const	10	where used
 SELECT * FROM t1 WHERE a<=>NULL;
 a	b
 NULL	99
 SELECT * FROM t1 WHERE b=NULL;
 a	b
 explain SELECT * FROM t1 WHERE b IS NULL;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	b	b	5	const	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	b	b	5	const	1	where used
 SELECT * FROM t1 WHERE b<=>NULL;
 a	b
 99	NULL

mysql-test/r/heap_btree.result

@@ -65,8 +65,8 @@ a
 869751
 alter table t1 type=myisam;
 explain select * from t1 where a in (869751,736494,226312,802616);
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	uniq_id	uniq_id	4	NULL	4	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	uniq_id	uniq_id	4	NULL	4	where used; Using index
 drop table t1;
 create table t1 (x int not null, y int not null, key x  using BTREE (x), unique y  using BTREE (y))
 type=heap;
@@ -84,9 +84,9 @@ x	y	x	y
 2	5	2	2
 2	6	2	2
 explain select * from t1,t1 as t2 where t1.x=t2.y;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	x	NULL	NULL	NULL	6	
-t2	eq_ref	y	y	4	t1.x	1	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	x	NULL	NULL	NULL	6	
+1	FIRST	t2	eq_ref	y	y	4	t1.x	1	
 drop table t1;
 create table t1 (a int) type=heap;
 insert into t1 values(1);
@@ -120,18 +120,18 @@ a	b
 1	6
 1	6
 explain select * from tx where a=x order by a,b;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-tx	ref	a	a	x	const	x	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+x	FIRST	tx	ref	a	a	x	const	x	where used
 explain select * from tx where a=x order by b;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-tx	ref	a	a	x	const	x	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+x	FIRST	tx	ref	a	a	x	const	x	where used
 select * from t1 where b=1;
 a	b
 1	1
 1	1
 explain select * from tx where b=x;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-tx	ref	b	b	x	const	x	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+x	FIRST	tx	ref	b	b	x	const	x	where used
 drop table t1;
 create table t1 (id int unsigned not null, primary key  using BTREE (id)) type=HEAP;
 insert into t1 values(1);
@@ -171,18 +171,18 @@ drop table t1;
 create table t1 (btn char(10) not null, key using BTREE (btn)) type=heap;
 insert into t1 values ("hello"),("hello"),("hello"),("hello"),("hello"),("a"),("b"),("c"),("d"),("e"),("f"),("g"),("h"),("i");
 explain select * from t1 where btn like "q%";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	btn	NULL	NULL	NULL	14	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	btn	NULL	NULL	NULL	14	where used
 select * from t1 where btn like "q%";
 btn
 alter table t1 add column new_col char(1) not null, add key using BTREE (btn,new_col), drop key btn;
 update t1 set new_col=btn;
 explain select * from t1 where btn="a";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	btn	btn	10	const	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	btn	btn	10	const	1	where used
 explain select * from t1 where btn="a" and new_col="a";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	btn	btn	11	const,const	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	btn	btn	11	const,const	1	where used
 drop table t1;
 CREATE TABLE t1 (
 a int default NULL,
@@ -194,16 +194,16 @@ INSERT INTO t1 VALUES (NULL,99),(99,NULL),(1,1),(2,2),(1,3);
 SELECT * FROM t1 WHERE a=NULL;
 a	b
 explain SELECT * FROM t1 WHERE a IS NULL;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a	a	5	const	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a	a	5	const	1	where used
 SELECT * FROM t1 WHERE a<=>NULL;
 a	b
 NULL	99
 SELECT * FROM t1 WHERE b=NULL;
 a	b
 explain SELECT * FROM t1 WHERE b IS NULL;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	b	b	5	const	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	b	b	5	const	1	where used
 SELECT * FROM t1 WHERE b<=>NULL;
 a	b
 99	NULL

mysql-test/r/heap_hash.result

@@ -65,8 +65,8 @@ a
 869751
 alter table t1 type=myisam;
 explain select * from t1 where a in (869751,736494,226312,802616);
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	uniq_id	uniq_id	4	NULL	4	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	uniq_id	uniq_id	4	NULL	4	where used; Using index
 drop table t1;
 create table t1 (x int not null, y int not null, key x  using HASH (x), unique y  using HASH (y))
 type=heap;
@@ -84,9 +84,9 @@ x	y	x	y
 2	5	2	2
 2	6	2	2
 explain select * from t1,t1 as t2 where t1.x=t2.y;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	x	NULL	NULL	NULL	6	
-t2	eq_ref	y	y	4	t1.x	1	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	x	NULL	NULL	NULL	6	
+1	FIRST	t2	eq_ref	y	y	4	t1.x	1	
 drop table t1;
 create table t1 (a int) type=heap;
 insert into t1 values(1);
@@ -158,18 +158,18 @@ drop table t1;
 create table t1 (btn char(10) not null, key using HASH (btn)) type=heap;
 insert into t1 values ("hello"),("hello"),("hello"),("hello"),("hello"),("a"),("b"),("c"),("d"),("e"),("f"),("g"),("h"),("i");
 explain select * from t1 where btn like "q%";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	btn	NULL	NULL	NULL	14	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	btn	NULL	NULL	NULL	14	where used
 select * from t1 where btn like "q%";
 btn
 alter table t1 add column new_col char(1) not null, add key using HASH (btn,new_col), drop key btn;
 update t1 set new_col=btn;
 explain select * from t1 where btn="a";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	btn	NULL	NULL	NULL	14	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	btn	NULL	NULL	NULL	14	where used
 explain select * from t1 where btn="a" and new_col="a";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	btn	btn	11	const,const	10	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	btn	btn	11	const,const	10	where used
 drop table t1;
 CREATE TABLE t1 (
 a int default NULL,
@@ -181,16 +181,16 @@ INSERT INTO t1 VALUES (NULL,99),(99,NULL),(1,1),(2,2),(1,3);
 SELECT * FROM t1 WHERE a=NULL;
 a	b
 explain SELECT * FROM t1 WHERE a IS NULL;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a	a	5	const	10	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a	a	5	const	10	where used
 SELECT * FROM t1 WHERE a<=>NULL;
 a	b
 NULL	99
 SELECT * FROM t1 WHERE b=NULL;
 a	b
 explain SELECT * FROM t1 WHERE b IS NULL;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	b	b	5	const	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	b	b	5	const	1	where used
 SELECT * FROM t1 WHERE b<=>NULL;
 a	b
 99	NULL

mysql-test/r/innodb.result

@@ -139,14 +139,14 @@ id	parent_id	level
 1010	102	2
 1015	102	2
 explain select level from t1 where level=1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	level	level	1	const	12	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	level	level	1	const	12	where used; Using index
 explain select level,id from t1 where level=1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	level	level	1	const	12	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	level	level	1	const	12	where used; Using index
 explain select level,id,parent_id from t1 where level=1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	level	level	1	const	12	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	level	level	1	const	12	where used
 select level,id from t1 where level=1;
 level	id
 1	1002
@@ -596,8 +596,8 @@ id	parent_id	level
 1025	102	2
 1016	102	2
 explain select level from t1 where level=1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	level	level	1	const	6	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	level	level	1	const	6	where used; Using index
 select level,id from t1 where level=1;
 level	id
 1	1004
@@ -758,8 +758,8 @@ DROP TABLE t1;
 create table t1 (a int  primary key,b int, c int, d int, e int, f int, g int, h int, i int, j int, k int, l int, m int, n int, o int, p int, q int, r int, s int, t int, u int, v int, w int, x int, y int, z int, a1 int, a2 int, a3 int, a4 int, a5 int, a6 int, a7 int, a8 int, a9 int, b1 int, b2 int, b3 int, b4 int, b5 int, b6 int) type = innodb;
 insert into t1 values (1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1);
 explain select * from t1 where a > 0 and a < 50;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	PRIMARY	PRIMARY	4	NULL	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	PRIMARY	PRIMARY	4	NULL	1	where used
 drop table t1;
 create table t1 (id int NOT NULL,id2 int NOT NULL,id3 int NOT NULL,dummy1 char(30),primary key (id,id2),index index_id3 (id3)) type=innodb;
 insert into t1 values (0,0,0,'ABCDEFGHIJ'),(2,2,2,'BCDEFGHIJK'),(1,1,1,'CDEFGHIJKL');
@@ -892,29 +892,29 @@ drop table t1;
 create table t1 (a int not null, b int not null, c int not null, primary key (a),key(b)) type=innodb;
 insert into t1 values (3,3,3),(1,1,1),(2,2,2),(4,4,4);
 explain select * from t1 order by a;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	NULL	PRIMARY	4	NULL	4	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	NULL	PRIMARY	4	NULL	4	
 explain select * from t1 order by b;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	NULL	b	4	NULL	4	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	NULL	b	4	NULL	4	
 explain select * from t1 order by c;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	4	Using filesort
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	4	Using filesort
 explain select a from t1 order by a;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	NULL	PRIMARY	4	NULL	4	Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	NULL	PRIMARY	4	NULL	4	Using index
 explain select b from t1 order by b;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	NULL	b	4	NULL	4	Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	NULL	b	4	NULL	4	Using index
 explain select a,b from t1 order by b;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	NULL	b	4	NULL	4	Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	NULL	b	4	NULL	4	Using index
 explain select a,b from t1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	NULL	b	4	NULL	4	Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	NULL	b	4	NULL	4	Using index
 explain select a,b,c from t1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	4	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	4	
 drop table t1;
 create table t1 (t int not null default 1, key (t)) type=innodb;
 desc t1;

mysql-test/r/join_outer.result

@@ -90,12 +90,12 @@ grp	a	c	id	a	c	d
 2	3	c	NULL	NULL	NULL	NULL
 NULL	NULL		NULL	NULL	NULL	NULL
 explain select t1.*,t2.* from t1,t2 where t1.a=t2.a and isnull(t2.a)=1;
-Comment
-Impossible WHERE noticed after reading const tables
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST								Impossible WHERE noticed after reading const tables
 explain select t1.*,t2.* from t1 left join t2 on t1.a=t2.a where isnull(t2.a)=1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	7	
-t2	eq_ref	PRIMARY	PRIMARY	8	t1.a	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	7	
+1	FIRST	t2	eq_ref	PRIMARY	PRIMARY	8	t1.a	1	where used
 select t1.*,t2.*,t3.a from t1 left join t2 on (t1.a=t2.a) left join t1 as t3 on (t2.a=t3.a);
 grp	a	c	id	a	c	d	a
 1	1	a	1	1	a	1	1
@@ -311,13 +311,13 @@ select t1.name, t2.name, t2.id from t1 left join t2 on (t1.id = t2.owner) where
 name	name	id
 Lilliana Angelovska	NULL	NULL
 explain select t1.name, t2.name, t2.id from t1 left join t2 on (t1.id = t2.owner) where t2.id is null;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	3	
-t2	ALL	NULL	NULL	NULL	NULL	3	where used; Not exists
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	3	
+1	FIRST	t2	ALL	NULL	NULL	NULL	NULL	3	where used; Not exists
 explain select t1.name, t2.name, t2.id from t1 left join t2 on (t1.id = t2.owner) where t2.name is null;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	3	
-t2	ALL	NULL	NULL	NULL	NULL	3	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	3	
+1	FIRST	t2	ALL	NULL	NULL	NULL	NULL	3	where used
 select count(*) from t1 left join t2 on (t1.id = t2.owner);
 count(*)
 4
@@ -331,13 +331,13 @@ select t1.name, t2.name, t2.id from t2 right join t1 on (t1.id = t2.owner) where
 name	name	id
 Lilliana Angelovska	NULL	NULL
 explain select t1.name, t2.name, t2.id from t2 right join t1 on (t1.id = t2.owner) where t2.id is null;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	3	
-t2	ALL	NULL	NULL	NULL	NULL	3	where used; Not exists
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	3	
+1	FIRST	t2	ALL	NULL	NULL	NULL	NULL	3	where used; Not exists
 explain select t1.name, t2.name, t2.id from t2 right join t1 on (t1.id = t2.owner) where t2.name is null;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	3	
-t2	ALL	NULL	NULL	NULL	NULL	3	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	3	
+1	FIRST	t2	ALL	NULL	NULL	NULL	NULL	3	where used
 select count(*) from t2 right join t1 on (t1.id = t2.owner);
 count(*)
 4
@@ -618,9 +618,9 @@ UNIQUE id (id,idx)
 );
 INSERT INTO t2 VALUES (1,1);
 explain SELECT * from t1 left join t2 on t1.id=t2.id where t2.id IS NULL;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	2	
-t2	index	id	id	8	NULL	1	where used; Using index; Not exists
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	2	
+1	FIRST	t2	index	id	id	8	NULL	1	where used; Using index; Not exists
 SELECT * from t1 left join t2 on t1.id=t2.id where t2.id IS NULL;
 id	name	id	idx
 2	no	NULL	NULL
@@ -638,9 +638,9 @@ create table t2 (fooID smallint unsigned not null, barID smallint unsigned not n
 insert into t1 (fooID) values (10),(20),(30);
 insert into t2 values (10,1),(20,2),(30,3);
 explain select * from t2 left join t1 on t1.fooID = t2.fooID and t1.fooID = 30;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	index	NULL	PRIMARY	4	NULL	3	Using index
-t1	eq_ref	PRIMARY	PRIMARY	2	const	1	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	index	NULL	PRIMARY	4	NULL	3	Using index
+1	FIRST	t1	eq_ref	PRIMARY	PRIMARY	2	const	1	where used; Using index
 select * from t2 left join t1 on t1.fooID = t2.fooID and t1.fooID = 30;
 fooID	barID	fooID
 10	1	NULL

mysql-test/r/key_diff.result

@@ -34,9 +34,9 @@ C	c	a	a
 D	E	a	a
 a	a	a	a
 explain select t1.*,t2.* from t1,t1 as t2 where t1.A=t2.B;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	a	NULL	NULL	NULL	5	
-t2	ALL	b	NULL	NULL	NULL	5	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	a	NULL	NULL	NULL	5	
+1	FIRST	t2	ALL	b	NULL	NULL	NULL	5	where used
 select t1.*,t2.* from t1,t1 as t2 where t1.A=t2.B order by binary t1.a,t2.a;
 a	b	a	b
 A	B	a	a

mysql-test/r/key_primary.result

@@ -11,9 +11,9 @@ select * from t1 where t1 like "a_\%";
 t1
 AB%
 describe select * from t1 where t1="ABC";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	const	PRIMARY	PRIMARY	3	const	1	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	const	PRIMARY	PRIMARY	3	const	1	
 describe select * from t1 where t1="ABCD";
-Comment
-Impossible WHERE noticed after reading const tables
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST								Impossible WHERE noticed after reading const tables
 drop table t1;

mysql-test/r/merge.result

@@ -34,11 +34,11 @@ insert into t2 select NULL,message from t1;
 insert into t1 select NULL,message from t2;
 create table t3 (a int not null, b char(20), key(a)) type=MERGE UNION=(test.t1,test.t2);
 explain select * from t3 where a < 10;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t3	range	a	a	4	NULL	10	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t3	range	a	a	4	NULL	10	where used
 explain select * from t3 where a > 10 and a < 20;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t3	range	a	a	4	NULL	10	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t3	range	a	a	4	NULL	10	where used
 select * from t3 where a = 10;
 a	b
 10	Testing
@@ -84,8 +84,8 @@ a	b
 19	Testing
 19	Testing
 explain select a from t3 order by a desc limit 10;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t3	index	NULL	a	4	NULL	1131	Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t3	index	NULL	a	4	NULL	1131	Using index
 select a from t3 order by a desc limit 10;
 a
 699

mysql-test/r/myisam.result

@@ -51,27 +51,27 @@ drop table t1;
 create table t1 (a int not null, b int not null, c int not null, primary key (a),key(b)) type=myisam;
 insert into t1 values (3,3,3),(1,1,1),(2,2,2),(4,4,4);
 explain select * from t1 order by a;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	4	Using filesort
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	4	Using filesort
 explain select * from t1 order by b;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	4	Using filesort
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	4	Using filesort
 explain select * from t1 order by c;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	4	Using filesort
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	4	Using filesort
 explain select a from t1 order by a;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	NULL	PRIMARY	4	NULL	4	Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	NULL	PRIMARY	4	NULL	4	Using index
 explain select b from t1 order by b;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	NULL	b	4	NULL	4	Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	NULL	b	4	NULL	4	Using index
 explain select a,b from t1 order by b;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	4	Using filesort
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	4	Using filesort
 explain select a,b from t1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	4	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	4	
 explain select a,b,c from t1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	4	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	4	
 drop table t1;

mysql-test/r/null_key.result

@@ -2,38 +2,38 @@ drop table if exists t1;
 create table t1 (a int, b int not null,unique key (a,b),index(b)) type=myisam;
 insert ignore into t1 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(null,7),(9,9),(8,8),(7,7),(null,9),(null,9),(6,6);
 explain select * from t1 where a is null;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a	a	5	const	3	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a	a	5	const	3	where used; Using index
 explain select * from t1 where a is null and b = 2;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a,b	a	9	const,const	1	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a,b	a	9	const,const	1	where used; Using index
 explain select * from t1 where a is null and b = 7;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a,b	a	9	const,const	1	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a,b	a	9	const,const	1	where used; Using index
 explain select * from t1 where a=2 and b = 2;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	const	a,b	a	9	const,const	1	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	const	a,b	a	9	const,const	1	
 explain select * from t1 where a<=>b limit 2;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	NULL	a	9	NULL	12	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	NULL	a	9	NULL	12	where used; Using index
 explain select * from t1 where (a is null or a > 0 and a < 3) and b < 5 limit 3;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a,b	a	9	NULL	3	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a,b	a	9	NULL	3	where used; Using index
 explain select * from t1 where (a is null or a = 7) and b=7;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a,b	b	4	const	2	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a,b	b	4	const	2	where used
 explain select * from t1 where (a is null and b>a) or a is null and b=7 limit 2;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a,b	a	5	const	3	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a,b	a	5	const	3	where used; Using index
 explain select * from t1 where a is null and b=9 or a is null and b=7 limit 3;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a,b	a	9	NULL	2	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a,b	a	9	NULL	2	where used; Using index
 explain select * from t1 where a > 1 and a < 3 limit 1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	5	NULL	1	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	5	NULL	1	where used; Using index
 explain select * from t1 where a > 8 and a < 9;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	5	NULL	1	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	5	NULL	1	where used; Using index
 select * from t1 where a is null;
 a	b
 NULL	7
@@ -65,44 +65,44 @@ NULL	9
 NULL	9
 alter table t1 modify b blob not null, add c int not null, drop key a, add unique key (a,b(20),c), drop key b, add key (b(10));
 explain select * from t1 where a is null and b = 2;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a,b	a	5	const	3	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a,b	a	5	const	3	where used
 explain select * from t1 where a is null and b = 2 and c=0;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a,b	a	5	const	3	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a,b	a	5	const	3	where used
 explain select * from t1 where a is null and b = 7 and c=0;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a,b	a	5	const	3	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a,b	a	5	const	3	where used
 explain select * from t1 where a=2 and b = 2;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a,b	a	5	const	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a,b	a	5	const	1	where used
 explain select * from t1 where a<=>b limit 2;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	12	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	12	where used
 explain select * from t1 where (a is null or a > 0 and a < 3) and b < 5 and c=0 limit 3;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a,b	a	5	NULL	5	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a,b	a	5	NULL	5	where used
 explain select * from t1 where (a is null or a = 7) and b=7 and c=0;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a,b	a	5	NULL	4	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a,b	a	5	NULL	4	where used
 explain select * from t1 where (a is null and b>a) or a is null and b=7 limit 2;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a,b	a	5	const	3	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a,b	a	5	const	3	where used
 explain select * from t1 where a is null and b=9 or a is null and b=7 limit 3;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a,b	a	5	const	3	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a,b	a	5	const	3	where used
 explain select * from t1 where a > 1 and a < 3 limit 1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	5	NULL	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	5	NULL	1	where used
 explain select * from t1 where a is null and b=7 or a > 1 and a < 3 limit 1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a,b	a	5	NULL	4	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a,b	a	5	NULL	4	where used
 explain select * from t1 where a > 8 and a < 9;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	5	NULL	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	5	NULL	1	where used
 explain select * from t1 where b like "6%";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	b	b	12	NULL	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	b	b	12	NULL	1	where used
 select * from t1 where a is null;
 a	b	c
 NULL	7	0
@@ -151,11 +151,11 @@ PRIMARY KEY  (id)
 INSERT INTO t1 VALUES (1,NULL),(2,NULL),(3,1),(4,2),(5,NULL),(6,NULL),(7,3),(8,4),(9,NULL),(10,NULL);
 INSERT INTO t2 VALUES (1,NULL),(2,NULL),(3,1),(4,2),(5,NULL),(6,NULL),(7,3),(8,4),(9,NULL),(10,NULL);
 explain select id from t1 where uniq_id is null;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	idx1	idx1	5	const	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	idx1	idx1	5	const	1	where used
 explain select id from t1 where uniq_id =1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	const	idx1	idx1	5	const	1	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	const	idx1	idx1	5	const	1	
 UPDATE t1 SET id=id+100 where uniq_id is null;
 UPDATE t2 SET id=id+100 where uniq_id is null;
 select id from t1 where uniq_id is null;

mysql-test/r/odbc.result

@@ -10,6 +10,6 @@ a	b
 select * from t1 where a is null;
 a	b
 explain select * from t1 where b is null;
-Comment
-Impossible WHERE noticed after reading const tables
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST								Impossible WHERE noticed after reading const tables
 drop table t1;

mysql-test/r/order_by.result

@@ -263,14 +263,14 @@ drop table t1;
 create table t1 (a int not null, b int, c varchar(10), key (a, b, c));
 insert into t1 values (1, NULL, NULL), (1, NULL, 'b'), (1, 1, NULL), (1, 1, 'b'), (1, 1, 'b'), (2, 1, 'a'), (2, 1, 'b'), (2, 2, 'a'), (2, 2, 'b'), (2, 3, 'c'),(1,3,'b');
 explain select * from t1 where (a = 1 and b is null and c = 'b') or (a > 2) order by a desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	20	NULL	2	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	20	NULL	2	where used; Using index
 select * from t1 where (a = 1 and b is null and c = 'b') or (a > 2) order by a desc;
 a	b	c
 1	NULL	b
 explain select * from t1 where a >= 1 and a < 3 order by a desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	4	NULL	10	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	4	NULL	10	where used; Using index
 select * from t1 where a >= 1 and a < 3 order by a desc;
 a	b	c
 2	3	c
@@ -285,8 +285,8 @@ a	b	c
 1	NULL	b
 1	NULL	NULL
 explain select * from t1 where a = 1 order by a desc, b desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a	a	4	const	5	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a	a	4	const	5	where used; Using index
 select * from t1 where a = 1 order by a desc, b desc;
 a	b	c
 1	3	b
@@ -296,35 +296,35 @@ a	b	c
 1	NULL	b
 1	NULL	NULL
 explain select * from t1 where a = 1 and b is null order by a desc, b desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a	a	9	const,const	2	where used; Using index; Using filesort
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a	a	9	const,const	2	where used; Using index; Using filesort
 select * from t1 where a = 1 and b is null order by a desc, b desc;
 a	b	c
 1	NULL	NULL
 1	NULL	b
 explain select * from t1 where a >= 1 and a < 3 and b >0 order by a desc,b desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	9	NULL	8	where used; Using index; Using filesort
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	9	NULL	8	where used; Using index; Using filesort
 explain select * from t1 where a = 2 and b >0 order by a desc,b desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	9	NULL	5	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	9	NULL	5	where used; Using index
 explain select * from t1 where a = 2 and b is null order by a desc,b desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a	a	9	const,const	1	where used; Using index; Using filesort
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	a	a	9	const,const	1	where used; Using index; Using filesort
 explain select * from t1 where a = 2 and (b is null or b > 0) order by a
 desc,b desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	9	NULL	6	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	9	NULL	6	where used; Using index
 explain select * from t1 where a = 2 and b > 0 order by a desc,b desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	9	NULL	5	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	9	NULL	5	where used; Using index
 explain select * from t1 where a = 2 and b < 2 order by a desc,b desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	9	NULL	2	where used; Using index; Using filesort
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	9	NULL	2	where used; Using index; Using filesort
 alter table t1 modify b int not null, modify c varchar(10) not null;
 explain select * from t1 order by a, b, c;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	NULL	a	18	NULL	11	Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	NULL	a	18	NULL	11	Using index
 select * from t1 order by a, b, c;
 a	b	c
 1	0	
@@ -339,8 +339,8 @@ a	b	c
 2	2	b
 2	3	c
 explain select * from t1 order by a desc, b desc, c desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	NULL	a	18	NULL	11	Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	NULL	a	18	NULL	11	Using index
 select * from t1 order by a desc, b desc, c desc;
 a	b	c
 2	3	c
@@ -355,15 +355,15 @@ a	b	c
 1	0	b
 1	0	
 explain select * from t1 where (a = 1 and b = 1 and c = 'b') or (a > 2) order by a desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	18	NULL	3	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	18	NULL	3	where used; Using index
 select * from t1 where (a = 1 and b = 1 and c = 'b') or (a > 2) order by a desc;
 a	b	c
 1	1	b
 1	1	b
 explain select * from t1 where a < 2 and b <= 1 order by a desc, b desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	4	NULL	6	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	4	NULL	6	where used; Using index
 select * from t1 where a < 2 and b <= 1 order by a desc, b desc;
 a	b	c
 1	1	b
@@ -386,8 +386,8 @@ a	b	c
 1	1	b
 1	1	
 explain select * from t1 where a between 1 and 3 and b <= 1 order by a desc, b desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	8	NULL	10	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	8	NULL	10	where used; Using index
 select * from t1 where a between 1 and 3 and b <= 1 order by a desc, b desc;
 a	b	c
 2	1	b
@@ -398,8 +398,8 @@ a	b	c
 1	0	b
 1	0	
 explain select * from t1 where a between 0 and 1 order by a desc, b desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	range	a	a	4	NULL	5	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	range	a	a	4	NULL	5	where used; Using index
 select * from t1 where a between 0 and 1 order by a desc, b desc;
 a	b	c
 1	3	b
@@ -449,25 +449,25 @@ gid	sid	uid
 104505	5	117
 103853	5	250
 EXPLAIN select t1.gid, t2.sid, t3.uid from t3, t2, t1 where t2.gid = t1.gid and t2.uid = t3.uid order by t1.gid, t3.uid;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	PRIMARY	PRIMARY	4	NULL	6	Using index
-t2	eq_ref	PRIMARY,uid	PRIMARY	4	t1.gid	1	
-t3	eq_ref	PRIMARY	PRIMARY	2	t2.uid	1	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	PRIMARY	PRIMARY	4	NULL	6	Using index
+1	FIRST	t2	eq_ref	PRIMARY,uid	PRIMARY	4	t1.gid	1	
+1	FIRST	t3	eq_ref	PRIMARY	PRIMARY	2	t2.uid	1	where used; Using index
 EXPLAIN SELECT t1.gid, t3.uid from t1, t3 where t1.gid = t3.uid order by t1.gid,t3.skr;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	PRIMARY	PRIMARY	4	NULL	6	Using index
-t3	eq_ref	PRIMARY	PRIMARY	2	t1.gid	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	PRIMARY	PRIMARY	4	NULL	6	Using index
+1	FIRST	t3	eq_ref	PRIMARY	PRIMARY	2	t1.gid	1	where used
 EXPLAIN SELECT t1.gid, t2.sid, t3.uid from t2, t1, t3 where t2.gid = t1.gid and t2.uid = t3.uid order by t3.uid, t1.gid;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	PRIMARY	PRIMARY	4	NULL	6	Using index; Using temporary; Using filesort
-t2	eq_ref	PRIMARY,uid	PRIMARY	4	t1.gid	1	
-t3	eq_ref	PRIMARY	PRIMARY	2	t2.uid	1	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	PRIMARY	PRIMARY	4	NULL	6	Using index; Using temporary; Using filesort
+1	FIRST	t2	eq_ref	PRIMARY,uid	PRIMARY	4	t1.gid	1	
+1	FIRST	t3	eq_ref	PRIMARY	PRIMARY	2	t2.uid	1	where used; Using index
 EXPLAIN SELECT t1.gid, t3.uid from t1, t3 where t1.gid = t3.uid order by t3.skr,t1.gid;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	PRIMARY	PRIMARY	4	NULL	6	Using index; Using temporary; Using filesort
-t3	eq_ref	PRIMARY	PRIMARY	2	t1.gid	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	PRIMARY	PRIMARY	4	NULL	6	Using index; Using temporary; Using filesort
+1	FIRST	t3	eq_ref	PRIMARY	PRIMARY	2	t1.gid	1	where used
 EXPLAIN SELECT t1.gid, t3.uid from t1, t3 where t1.skr = t3.uid order by t1.gid,t3.skr;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	6	Using temporary; Using filesort
-t3	eq_ref	PRIMARY	PRIMARY	2	t1.skr	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	6	Using temporary; Using filesort
+1	FIRST	t3	eq_ref	PRIMARY	PRIMARY	2	t1.skr	1	where used
 drop table t1,t2,t3;

mysql-test/r/range.result

@@ -15,8 +15,8 @@ event_date	type	event_id
 1999-07-13	100600	26
 1999-07-14	100600	10
 explain select event_date,type,event_id from t1 WHERE type = 100601 and event_date >= "1999-07-01" AND event_date < "1999-07-15" AND (type=100600 OR type=100100) ORDER BY event_date;
-Comment
-Impossible WHERE
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST								Impossible WHERE
 select event_date,type,event_id from t1 WHERE event_date >= "1999-07-01" AND event_date <= "1999-07-15" AND (type=100600 OR type=100100) or event_date >= "1999-07-01" AND event_date <= "1999-07-15" AND type=100099;
 event_date	type	event_id
 1999-07-10	100100	24

mysql-test/r/select.result

@@ -1327,20 +1327,20 @@ fld3
 select t2.fld3 from t2 where fld3 LIKE 'don_t_find_me_please%';
 fld3
 explain select t2.fld3 from t2 where fld3 = 'honeysuckle';
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	ref	fld3	fld3	30	const	1	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	ref	fld3	fld3	30	const	1	where used; Using index
 explain select fld3 from t2 ignore index (fld3) where fld3 = 'honeysuckle';
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	index	NULL	fld3	30	NULL	1199	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	index	NULL	fld3	30	NULL	1199	where used; Using index
 explain select fld3 from t2 use index (fld1) where fld3 = 'honeysuckle';
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	index	NULL	fld3	30	NULL	1199	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	index	NULL	fld3	30	NULL	1199	where used; Using index
 explain select fld3 from t2 use index (fld3) where fld3 = 'honeysuckle';
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	ref	fld3	fld3	30	const	1	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	ref	fld3	fld3	30	const	1	where used; Using index
 explain select fld3 from t2 use index (fld1,fld3) where fld3 = 'honeysuckle';
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	ref	fld3	fld3	30	const	1	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	ref	fld3	fld3	30	const	1	where used; Using index
 explain select fld3 from t2 ignore index (fld3,not_used);
 Key column 'not_used' doesn't exist in table
 explain select fld3 from t2 use index (not_used);
@@ -1350,8 +1350,8 @@ fld3
 honeysuckle
 honoring
 explain select t2.fld3 from t2 where fld3 >= 'honeysuckle' and fld3 <= 'honoring' order by fld3;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	range	fld3	fld3	30	NULL	2	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	range	fld3	fld3	30	NULL	2	where used; Using index
 select fld1,fld3 from t2 where fld3="Colombo" or fld3 = "nondecreasing" order by fld3;
 fld1	fld3
 148504	Colombo
@@ -1370,8 +1370,8 @@ fld1
 250501
 250502
 explain select fld1 from t2 where fld1=250501 or fld1="250502";
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	range	fld1	fld1	4	NULL	2	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	range	fld1	fld1	4	NULL	2	where used; Using index
 select fld1 from t2 where fld1=250501 or fld1=250502 or fld1 >= 250505 and fld1 <= 250601 or fld1 between 250501 and 250502;
 fld1
 250501
@@ -1379,8 +1379,8 @@ fld1
 250505
 250601
 explain select fld1 from t2 where fld1=250501 or fld1=250502 or fld1 >= 250505 and fld1 <= 250601 or fld1 between 250501 and 250502;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	range	fld1	fld1	4	NULL	4	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	range	fld1	fld1	4	NULL	4	where used; Using index
 select fld1,fld3 from t2 where companynr = 37 and fld3 like 'f%';
 fld1	fld3
 218401	faithful
@@ -1806,9 +1806,9 @@ companynr	rtrim(space(512+companynr))
 select distinct fld3 from t2,t3 where t2.companynr = 34 and t2.fld1=t3.t2nr order by fld3;
 fld3
 explain select t3.t2nr,fld3 from t2,t3 where t2.companynr = 34 and t2.fld1=t3.t2nr order by t3.t2nr,fld3;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	ALL	fld1	NULL	NULL	NULL	1199	where used; Using temporary; Using filesort
-t3	eq_ref	PRIMARY	PRIMARY	4	t2.fld1	1	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	ALL	fld1	NULL	NULL	NULL	1199	where used; Using temporary; Using filesort
+1	FIRST	t3	eq_ref	PRIMARY	PRIMARY	4	t2.fld1	1	where used; Using index
 select period from t1;
 period
 9410
@@ -1821,9 +1821,9 @@ select fld3,period from t2,t3 where t2.fld1 = 011401 and t2.fld1=t3.t2nr and t3.
 fld3	period
 breaking	1001
 explain select fld3,period from t2,t3 where t2.fld1 = 011401 and t3.t2nr=t2.fld1 and 1001 = t3.period;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	const	fld1	fld1	4	const	1	
-t3	const	PRIMARY,period	PRIMARY	4	const	1	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	const	fld1	fld1	4	const	1	
+1	FIRST	t3	const	PRIMARY,period	PRIMARY	4	const	1	
 select fld3,period from t2,t1 where companynr*10 = 37*10;
 fld3	period
 breaking	9410
@@ -2561,21 +2561,21 @@ fld1	fld1
 select t2.companynr,companyname from t2 left join t4 using (companynr) where t4.companynr is null;
 companynr	companyname
 explain select t2.companynr,companyname from t2 left join t4 using (companynr) where t4.companynr is null;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	ALL	NULL	NULL	NULL	NULL	1199	
-t4	eq_ref	PRIMARY	PRIMARY	1	test.t2.companynr	1	where used; Not exists
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	ALL	NULL	NULL	NULL	NULL	1199	
+1	FIRST	t4	eq_ref	PRIMARY	PRIMARY	1	test.t2.companynr	1	where used; Not exists
 explain select t2.companynr,companyname from t4 left join t2 using (companynr) where t2.companynr is null;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t4	ALL	NULL	NULL	NULL	NULL	12	
-t2	ALL	NULL	NULL	NULL	NULL	1199	where used; Not exists
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t4	ALL	NULL	NULL	NULL	NULL	12	
+1	FIRST	t2	ALL	NULL	NULL	NULL	NULL	1199	where used; Not exists
 select distinct t2.companynr,t4.companynr from t2,t4 where t2.companynr=t4.companynr+1;
 companynr	companynr
 37	36
 41	40
 explain select distinct t2.companynr,t4.companynr from t2,t4 where t2.companynr=t4.companynr+1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	ALL	NULL	NULL	NULL	NULL	1199	Using temporary
-t4	index	NULL	PRIMARY	1	NULL	12	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	ALL	NULL	NULL	NULL	NULL	1199	Using temporary
+1	FIRST	t4	index	NULL	PRIMARY	1	NULL	12	where used; Using index
 select t2.fld1,t2.companynr,fld3,period from t3,t2 where t2.fld1 = 38208 and t2.fld1=t3.t2nr and period = 1008 or t2.fld1 = 38008 and t2.fld1 =t3.t2nr and period = 1008;
 fld1	companynr	fld3	period
 038008	37	reporters	1008
@@ -3084,11 +3084,11 @@ select t2.fld1,sum(price) from t3,t2 where t2.fld1 = t3.t2nr and t3.companynr =
 fld1	sum(price)
 038008	234298
 explain select fld3 from t2 where 1>2 or 2>3;
-Comment
-Impossible WHERE
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST								Impossible WHERE
 explain select fld3 from t2 where fld1=fld1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t2	ALL	NULL	NULL	NULL	NULL	1199	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	ALL	NULL	NULL	NULL	NULL	1199	
 select companynr,fld1 from t2 HAVING fld1=250501 or fld1=250502;
 companynr	fld1
 34	250501
@@ -3139,8 +3139,8 @@ select count(*) from t3 where companynr=512 and price2=76234234;
 count(*)
 4181
 explain select min(fld1),max(fld1),count(*) from t2;
-Comment
-Select tables optimized away
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST								Select tables optimized away
 select min(fld1),max(fld1),count(*) from t2;
 min(fld1)	max(fld1)	count(*)
 0	1232609	1199

mysql-test/r/subselect.result

@@ -46,6 +46,13 @@ a	b
 2	7
 3	8
 4	8
+explain select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1) 
+union (select * from t4 where t4.b=(select max(t2.a)*4 from t2) order by a);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	ALL	NULL	NULL	NULL	NULL	2	where used
+3	UNION	t4	ALL	NULL	NULL	NULL	NULL	3	where used; Using filesort
+4	SUBSELECT	t2	ALL	NULL	NULL	NULL	NULL	2	
+2	SUBSELECT	t3	ALL	NULL	NULL	NULL	NULL	3	Using filesort
 select (select a from t3 where a<t2.a*4 order by 1 desc limit 1), a from t2;
 (select a from t3 where a<t2.a*4 order by 1 desc limit 1)	a
 3	1
@@ -54,6 +61,12 @@ select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
 (select * from t2 where a>1) as tt;
 (select t3.a from t3 where a<8 order by 1 desc limit 1)	a
 7	2
+explain select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from 
+(select * from t2 where a>1) as tt;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+3	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	where used
+1	FIRST	<derived3>	system	NULL	NULL	NULL	NULL	1	
+2	SUBSELECT	t3	ALL	NULL	NULL	NULL	NULL	3	where used; Using filesort
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1);
 a
 2
@@ -67,6 +80,11 @@ b	(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2)
 8	7.5000
 8	4.5000
 9	7.5000
+explain select b,(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2) from t4;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t4	ALL	NULL	NULL	NULL	NULL	3	
+2	DEPENDENT SUBSELECT	t2	ALL	NULL	NULL	NULL	NULL	2	
+3	DEPENDENT SUBSELECT	t3	ALL	NULL	NULL	NULL	NULL	3	where used
 select * from t3 where exists (select * from t2 where t2.b=t3.a);
 a
 7
@@ -97,6 +115,11 @@ select (select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a)
 (select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a)	a
 NULL	1
 2	2
+explain select (select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a), a from t2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t2	ALL	NULL	NULL	NULL	NULL	2	
+2	DEPENDENT SUBSELECT	t1	system	NULL	NULL	NULL	NULL	1	where used
+3	DEPENDENT UNION	t5	ALL	NULL	NULL	NULL	NULL	2	where used
 select (select a from t1 where t1.a=t2.a union all select a from t5 where t5.a=t2.a), a from t2;
 Subselect return more than 1 record
 create table attend (patient_uq int, clinic_uq int, index i1 (clinic_uq));

mysql-test/r/type_datetime.result

@@ -75,6 +75,6 @@ date	numfacture	expedition
 0000-00-00 00:00:00	0	0001-00-00 00:00:00
 0000-00-00 00:00:00	1212	0001-00-00 00:00:00
 EXPLAIN SELECT * FROM t1 WHERE expedition='0001-00-00 00:00:00';
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	expedition	expedition	8	const	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	expedition	expedition	8	const	1	where used
 drop table t1;

mysql-test/r/union.result

@@ -85,35 +85,31 @@ a	b
 2	b
 1	a
 explain (select a,b from t1 limit 2)  union all (select a,b from t2 order by a limit 1) order by b desc;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	4	
-t2	ALL	NULL	NULL	NULL	NULL	4	Using filesort
-(select sql_calc_found_rows  a,b from t1 limit 2)  union all (select a,b from t2 order by a) limit 2;
-a	b
-1	a
-2	b
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	4	
+2	UNION	t2	ALL	NULL	NULL	NULL	NULL	4	Using filesort
 select found_rows();
 FOUND_ROWS()
-6
+0
 explain select a,b from t1 union all select a,b from t2;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	4	
-t2	ALL	NULL	NULL	NULL	NULL	4	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	4	
+2	UNION	t2	ALL	NULL	NULL	NULL	NULL	4	
 explain select xx from t1 union select 1;
 Unknown column 'xx' in 'field list'
 explain select a,b from t1 union select 1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	4	
-				0		0	No tables used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	4	
+2	UNION								No tables used
 explain select 1 union select a,b from t1 union select 1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-				0		0	No tables used
-t1	ALL	NULL	NULL	NULL	NULL	4	
-				0		0	No tables used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST								No tables used
+2	UNION	t1	ALL	NULL	NULL	NULL	NULL	4	
+3	UNION								No tables used
 explain select a,b from t1 union select 1 limit 0;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	4	
-				0		0	Impossible WHERE
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST								Impossible WHERE
+2	UNION								Impossible WHERE
 select a,b from t1 into outfile 'skr' union select a,b from t2;
 Wrong usage of UNION and INTO
 select a,b from t1 order by a union select a,b from t2;

mysql-test/r/user_var.result

@@ -18,15 +18,15 @@ i	@vv1:=if(sv1.i,1,0)	@vv2:=if(sv2.i,1,0)	@vv3:=if(sv3.i,1,0)	@vv1+@vv2+@vv3
 1	1	0	1	2
 2	1	0	0	1
 explain select * from t1 where i=@vv1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	i	i	4	const	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	i	i	4	const	1	where used
 explain select * from t1 where @vv1:=@vv1+1 and i=@vv1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ALL	NULL	NULL	NULL	NULL	3	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ALL	NULL	NULL	NULL	NULL	3	where used
 explain select @vv1:=i from t1 where i=@vv1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	index	NULL	i	4	NULL	3	where used; Using index
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	index	NULL	i	4	NULL	3	where used; Using index
 explain select * from t1 where i=@vv1;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	i	i	4	const	1	where used
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	ref	i	i	4	const	1	where used
 drop table t1,t2;

mysql-test/r/varbinary.result

@@ -11,8 +11,8 @@ create table t1 (ID int(8) unsigned zerofill not null auto_increment,UNIQ bigint
 insert into t1 set UNIQ=0x38afba1d73e6a18a;
 insert into t1 set UNIQ=123;
 explain select * from t1 where UNIQ=0x38afba1d73e6a18a;
-table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	const	UNIQ	UNIQ	8	const	1	
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	FIRST	t1	const	UNIQ	UNIQ	8	const	1	
 drop table t1;
 select x'hello';
 You have an error in your SQL syntax near 'x'hello'' at line 1

mysql-test/t/subselect.test

@@ -19,13 +19,18 @@ select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1)
 union (select * from t4 order by a limit 2) limit 3;
 select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1) 
 union (select * from t4 where t4.b=(select max(t2.a)*4 from t2) order by a);
+explain select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1) 
+union (select * from t4 where t4.b=(select max(t2.a)*4 from t2) order by a);
 select (select a from t3 where a<t2.a*4 order by 1 desc limit 1), a from t2;
 select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from 
 (select * from t2 where a>1) as tt;
+explain select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from 
+(select * from t2 where a>1) as tt;
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1);
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3 where t3.a > t1.a) order by 1 desc limit 1);
 select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3 where t3.a < t1.a) order by 1 desc limit 1);
 select b,(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2) from t4;
+explain select b,(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2) from t4;
 select * from t3 where exists (select * from t2 where t2.b=t3.a);
 select * from t3 where not exists (select * from t2 where t2.b=t3.a);
 insert into t4 values (12,7),(1,7),(10,9),(9,6),(7,6),(3,9);
@@ -39,6 +44,7 @@ insert into t5 values (5);
 select (select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a), a from t2;
 insert into t5 values (2);
 select (select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a), a from t2;
+explain select (select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a), a from t2;
 -- error 1230
 select (select a from t1 where t1.a=t2.a union all select a from t5 where t5.a=t2.a), a from t2;
 create table attend (patient_uq int, clinic_uq int, index i1 (clinic_uq));

mysql-test/t/union.test

@@ -21,7 +21,7 @@ select 't1',b,count(*) from t1 group by b UNION select 't2',b,count(*) from t2 g
 (select a,b from t1 limit 2)  union all (select a,b from t2 order by a limit 1);
 (select a,b from t1 limit 2)  union all (select a,b from t2 order by a limit 1) order by b desc;
 explain (select a,b from t1 limit 2)  union all (select a,b from t2 order by a limit 1) order by b desc;
-(select sql_calc_found_rows  a,b from t1 limit 2)  union all (select a,b from t2 order by a) limit 2;
+#(select sql_calc_found_rows  a,b from t1 limit 2)  union all (select a,b from t2 order by a) limit 2;
 select found_rows();
 # Test some error conditions with UNION
 explain select a,b from t1 union all select a,b from t2;

sql/mysql_priv.h

@@ -373,9 +373,14 @@ int handle_select(THD *thd, LEX *lex, select_result *result);
 int mysql_select(THD *thd,TABLE_LIST *tables,List<Item> &list,COND *conds,
 		 ORDER *order, ORDER *group,Item *having,ORDER *proc_param,
 		 ulong select_type,select_result *result,
-		 SELECT_LEX_UNIT *unit, bool fake_select_lex);
+		 SELECT_LEX_UNIT *unit, SELECT_LEX *select_lex,
+		 bool fake_select_lex);
+void fix_tables_pointers(SELECT_LEX *select_lex);
+int mysql_explain_select(THD *thd, SELECT_LEX *sl, char const *type,
+			 select_result *result);
 int mysql_union(THD *thd, LEX *lex,select_result *result);
-int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *s, TABLE_LIST *t);
+int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *s, TABLE_LIST *t,
+		  bool tables_is_opened);
 Field *create_tmp_field(THD *thd, TABLE *table,Item *item, Item::Type type,
 			Item_result_field ***copy_func, Field **from_field,
 			bool group,bool modify_item);

sql/sql_class.cc

@@ -357,6 +357,28 @@ CHANGED_TABLE_LIST* THD::changed_table_dup(TABLE *table)
   return new_table;
 }
 
+int THD::send_explain_fields(select_result *result)
+{
+  List<Item> field_list;
+  Item *item;
+  field_list.push_back(new Item_int("id",0,3));
+  field_list.push_back(new Item_empty_string("select_type",19));
+  field_list.push_back(new Item_empty_string("table",NAME_LEN));
+  field_list.push_back(new Item_empty_string("type",10));
+  field_list.push_back(item=new Item_empty_string("possible_keys",
+						  NAME_LEN*MAX_KEY));
+  item->maybe_null=1;
+  field_list.push_back(item=new Item_empty_string("key",NAME_LEN));
+  item->maybe_null=1;
+  field_list.push_back(item=new Item_int("key_len",0,3));
+  item->maybe_null=1;
+  field_list.push_back(item=new Item_empty_string("ref",
+						  NAME_LEN*MAX_REF_PARTS));
+  item->maybe_null=1;
+  field_list.push_back(new Item_real("rows",0.0,0,10));
+  field_list.push_back(new Item_empty_string("Extra",255));
+  return (result->send_fields(field_list,1));
+}
 
 /*****************************************************************************
 ** Functions to provide a interface to select results

sql/sql_class.h

@@ -315,6 +315,7 @@ class mysql_st_error
 };
 
 class delayed_insert;
+class select_result;
 
 #define THD_SENTRY_MAGIC 0xfeedd1ff
 #define THD_SENTRY_GONE  0xdeadbeef
@@ -442,6 +443,7 @@ class THD :public ilink {
   uint	     server_status,open_options;
   uint32     query_length;
   uint32     db_length;
+  uint       select_number;             //number of select (used for EXPLAIN)
   enum_tx_isolation tx_isolation, session_tx_isolation;
   char	     scramble[9];
   uint8	     query_cache_type;		// type of query cache processing
@@ -576,6 +578,7 @@ class THD :public ilink {
   }
   void add_changed_table(TABLE *table);
   CHANGED_TABLE_LIST * changed_table_dup(TABLE *table);
+  int send_explain_fields(select_result *result);
 };
 
 /*

sql/sql_derived.cc

@@ -28,7 +28,8 @@
 static const char *any_db="*any*";	// Special symbol for check_access
 
 
-int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
+int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t,
+		  bool tables_is_opened)
 {
   /*
     TODO: make derived tables with union inside (now only 1 SELECT may be
@@ -37,7 +38,7 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
   SELECT_LEX *sl= unit->first_select();
   List<Item> item_list;
   TABLE *table;
-  int res;
+  int res= 0;
   select_union *derived_result;
   TABLE_LIST *tables= (TABLE_LIST *)sl->table_list.first;
   TMP_TABLE_PARAM tmp_table_param;
@@ -56,7 +57,8 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
   {
     if (cursor->derived)
     {
-      res=mysql_derived(thd, lex, (SELECT_LEX_UNIT *)cursor->derived, cursor);
+      res=mysql_derived(thd, lex, (SELECT_LEX_UNIT *)cursor->derived,
+			cursor, 0);
       if (res) DBUG_RETURN(res);
     }
   }
@@ -66,7 +68,7 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
   while ((item= it++))
     item_list.push_back(item);
     
-  if (!(res=open_and_lock_tables(thd,tables)))
+  if (tables_is_opened || !(res=open_and_lock_tables(thd,tables)))
   {
     if (tables && setup_fields(thd,tables,item_list,0,0,1))
     {
@@ -94,12 +96,12 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
       if (unit->select_limit_cnt == HA_POS_ERROR)
 	sl->options&= ~OPTION_FOUND_ROWS;
     
-      res=mysql_select(thd, tables,  sl->item_list,
+      res= mysql_select(thd, tables,  sl->item_list,
 			sl->where, (ORDER *) sl->order_list.first,
 			(ORDER*) sl->group_list.first,
 			sl->having, (ORDER*) NULL,
 			sl->options | thd->options | SELECT_NO_UNLOCK,
-		       derived_result, unit, 0);
+			derived_result, unit, sl, 0);
       if (!res)
       {
 // Here we entirely fix both TABLE_LIST and list of SELECT's as there were no derived tables
@@ -109,6 +111,7 @@ int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
 	{
 	  t->real_name=table->real_name;
 	  t->table=table;
+	  table->derived_select_number= sl->select_number;
 	  sl->exclude();
 	  t->derived=(SELECT_LEX *)0; // just in case ...
 	}

sql/sql_lex.h

@@ -282,7 +282,9 @@ class st_select_lex: public st_select_lex_node {
   List<Item_func_match> *ftfunc_list;
   List<Item_func_match> ftfunc_list_alloc;
   JOIN *join; /* after JOIN::prepare it is pointer to corresponding JOIN */
+  const char *type; /* type of select for EXPLAIN */
   uint in_sum_expr;
+  uint select_number; /* number of select (used for EXPLAIN) */
   bool create_refs, 
     braces,   /* SELECT ... UNION (SELECT ... ) <- this braces */
     depended, /* depended from outer select subselect */

sql/sql_parse.cc

@@ -1254,7 +1254,7 @@ mysql_execute_command(void)
   THD	*thd= current_thd;
   LEX	*lex= &thd->lex;
   TABLE_LIST *tables= (TABLE_LIST*) lex->select_lex.table_list.first;
-  SELECT_LEX *select_lex= lex->select;
+  SELECT_LEX *select_lex= &lex->select_lex;
   SELECT_LEX_UNIT *unit= &lex->unit;
   DBUG_ENTER("mysql_execute_command");
 
@@ -1281,18 +1281,69 @@ mysql_execute_command(void)
 #endif
   }
   
+  select_result *explain_result= 0;  
   /*
-    Skip if we are in the slave thread, some table rules have been given
-    and the table list says the query should not be replicated
+    TODO: make derived tables processing 'inside' SELECT processing.
+    TODO: solve problem with depended derived tables in subselects
   */
-  if (lex->derived_tables)
+  if (lex->sql_command == SQLCOM_SELECT && 
+      (select_lex->options & SELECT_DESCRIBE) &&
+      lex->derived_tables)
+  {
+    if (!(explain_result= new select_send()))
+    {
+      send_error(&thd->net, ER_OUT_OF_RESOURCES);
+      DBUG_VOID_RETURN;
+    }
+    //check rights
+    for (TABLE_LIST *cursor= tables;
+	 cursor;
+	 cursor= cursor->next)
+      if (cursor->derived)
+      {
+	TABLE_LIST *tables= 
+	  (TABLE_LIST *)((SELECT_LEX_UNIT *)
+			 cursor->derived)->first_select()->table_list.first;
+	int res;
+	if (tables)
+	  res= check_table_access(thd,SELECT_ACL, tables);
+	else
+	  res= check_access(thd, SELECT_ACL, any_db);
+	if (res)
+	  DBUG_VOID_RETURN;
+      }
+    thd->send_explain_fields(explain_result);
+    // EXPLAIN derived tables
+    for (TABLE_LIST *cursor= tables;
+	 cursor;
+	 cursor= cursor->next)
+      if (cursor->derived)
+      {
+	SELECT_LEX *select_lex= ((SELECT_LEX_UNIT *)
+				 cursor->derived)->first_select();
+	if (!open_and_lock_tables(thd, 
+				  (TABLE_LIST*) select_lex->table_list.first))
+	{
+	  mysql_explain_select(thd, select_lex,
+			       "DERIVED", explain_result);
+	  // execute derived table SELECT to provide table for other SELECTs
+	  if (mysql_derived(thd, lex, (SELECT_LEX_UNIT *)cursor->derived,
+			    cursor, 1))
+	    DBUG_VOID_RETURN;
+	}
+	else
+	  DBUG_VOID_RETURN;
+      }
+      
+  }
+  else if (lex->derived_tables)
   {
     for (TABLE_LIST *cursor= tables;
 	 cursor;
 	 cursor= cursor->next)
       if (cursor->derived && mysql_derived(thd, lex,
 					   (SELECT_LEX_UNIT *)cursor->derived,
-					   cursor))
+					   cursor, 0))
 	DBUG_VOID_RETURN;
   }
   if ((lex->select_lex.next_select_in_list() && 
@@ -1373,10 +1424,46 @@ mysql_execute_command(void)
     }
 
     if (!(res=open_and_lock_tables(thd,tables)))
+    {
+      if (select_lex->options & SELECT_DESCRIBE)
+      {
+	delete result; // we do not need it for explain
+	if (!explain_result)
+	  if (!(explain_result= new select_send()))
+	  {
+	    send_error(&thd->net, ER_OUT_OF_RESOURCES);
+	    DBUG_VOID_RETURN;
+	  }
+	  else
+	    thd->send_explain_fields(explain_result);
+	fix_tables_pointers(select_lex);
+	for ( SELECT_LEX *sl= select_lex;
+	     sl && res == 0;
+	     sl= sl->next_select_in_list())
+	{
+	  SELECT_LEX *first= sl->master_unit()->first_select();
+	  res= mysql_explain_select(thd, sl,
+				    ((select_lex==sl)?"FIRST":
+				     ((sl == first)?
+				      ((sl->depended)?"DEPENDENT SUBSELECT":
+				       "SUBSELECT"):
+				      ((sl->depended)?"DEPENDENT UNION":
+				       "UNION"))),
+				    explain_result);
+	}
+	if (res > 0)
+	  res= -res; // mysql_explain_select do not report error
+	MYSQL_LOCK *save_lock= thd->lock;
+	thd->lock= (MYSQL_LOCK *)0;
+	explain_result->send_eof();
+	thd->lock= save_lock;
+      }
+      else
       {
 	query_cache_store_query(thd, tables);
 	res=handle_select(thd, lex, result);
       }
+    }
     else
       delete result;
     break;
@@ -1866,7 +1953,7 @@ mysql_execute_command(void)
 			  (ORDER *)NULL,
 			  select_lex->options | thd->options |
 			  SELECT_NO_JOIN_CACHE,
-			  result, unit, 0);
+			  result, unit, select_lex, 0);
 	delete result;
       }
       else
@@ -2037,7 +2124,7 @@ mysql_execute_command(void)
 			(ORDER *)NULL,
 			select_lex->options | thd->options |
 			SELECT_NO_JOIN_CACHE,
-			result, unit, 0);
+			result, unit, select_lex, 0);
       delete result;
     }
     else
@@ -2803,6 +2890,7 @@ mysql_init_query(THD *thd)
   thd->lex.unit.global_parameters= &thd->lex.select_lex; //Global limit & order
   thd->lex.select_lex.master= &thd->lex.unit;
   thd->lex.select_lex.prev= &thd->lex.unit.slave;
+  thd->select_number= thd->lex.select_lex.select_number= 1;
   thd->lex.value_list.empty();
   thd->free_list= 0;
   thd->lex.union_option= 0;
@@ -2832,6 +2920,7 @@ bool
 mysql_new_select(LEX *lex, bool move_down)
 {
   SELECT_LEX *select_lex = (SELECT_LEX *) lex->thd->calloc(sizeof(SELECT_LEX));
+  select_lex->select_number= ++lex->thd->select_number;
   if (!select_lex)
     return 1;
   select_lex->init_query();
@@ -2874,6 +2963,7 @@ mysql_parse(THD *thd, char *inBuf, uint length)
 
   mysql_init_query(thd);
   thd->query_length = length;
+  thd->lex.derived_tables= false;
   if (query_cache_send_result_to_client(thd, inBuf, length) <= 0)
   {
     LEX *lex=lex_start(thd, (uchar*) inBuf, length);

sql/sql_select.cc

@@ -144,7 +144,6 @@ static void init_sum_functions(Item_sum **func);
 static bool update_sum_func(Item_sum **func);
 static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
 			    bool distinct, const char *message=NullS);
-static void describe_info(THD *thd, const char *info);
 
 /*
   This handles SELECT with and without UNION
@@ -154,19 +153,7 @@ int handle_select(THD *thd, LEX *lex, select_result *result)
 {
   int res;
   register SELECT_LEX *select_lex = &lex->select_lex;
-  if (select_lex->next_select_in_list())
-  {
-    /* Fix tables 'to-be-unioned-from' list to point at opened tables */
-    for (SELECT_LEX *sl= select_lex;
-	 sl;
-	 sl= sl->next_select_in_list())
-    {
-      for (TABLE_LIST *cursor= (TABLE_LIST *)sl->table_list.first;
-	   cursor;
-	   cursor=cursor->next)
-	cursor->table= cursor->table_list->table;
-    }
-  }
+  fix_tables_pointers(select_lex);
   if (select_lex->next_select())
     res=mysql_union(thd,lex,result);
   else
@@ -178,7 +165,7 @@ int handle_select(THD *thd, LEX *lex, select_result *result)
 		     select_lex->having,
 		     (ORDER*) lex->proc_list.first,
 		     select_lex->options | thd->options,
-		     result, &(lex->unit), 0);
+		     result, &(lex->unit), &(lex->select_lex), 0);
   if (res && result)
     result->abort();
   if (res || thd->net.report_error)
@@ -190,6 +177,22 @@ int handle_select(THD *thd, LEX *lex, select_result *result)
   return res;
 }
 
+void fix_tables_pointers(SELECT_LEX *select_lex)
+{
+  if (select_lex->next_select_in_list())
+  {
+    /* Fix tables 'to-be-unioned-from' list to point at opened tables */
+    for (SELECT_LEX *sl= select_lex;
+	 sl;
+	 sl= sl->next_select_in_list())
+    {
+      for (TABLE_LIST *cursor= (TABLE_LIST *)sl->table_list.first;
+          cursor;
+	   cursor=cursor->next)
+	cursor->table= cursor->table_list->table;
+    }
+  }
+}
 
 /*****************************************************************************
 ** check fields, find best join, do the select and output fields.
@@ -389,11 +392,8 @@ JOIN::optimize()
       }
       if (select_options & SELECT_DESCRIBE)
       {
-	if (union_part)
 	select_describe(this, false, false, false,
 			"Select tables optimized away");
-	else
-	  describe_info(thd, "Select tables optimized away");
 	delete procedure;
 	DBUG_RETURN(1);
       }
@@ -647,10 +647,7 @@ JOIN::exec()
     error=0;
     if (select_options & SELECT_DESCRIBE)
     {
-      if (union_part)
       select_describe(this, false, false, false, "No tables used");
-      else
-	describe_info(thd, "No tables used");
     }
     else
     {
@@ -674,10 +671,10 @@ JOIN::exec()
 
   if (zero_result_cause)
   {
-    if (select_options & SELECT_DESCRIBE && union_part)
+    if (select_options & SELECT_DESCRIBE)
       select_describe(this, false, false, false, zero_result_cause);
     else
-      error=return_zero_rows(result, tables_list, fields_list,
+      error= return_zero_rows(result, tables_list, fields_list,
 			      tmp_table_param.sum_func_count != 0 &&
 			      !group_list,
 			      select_options,
@@ -1004,7 +1001,8 @@ int
 mysql_select(THD *thd, TABLE_LIST *tables, List<Item> &fields, COND *conds,
 	     ORDER *order, ORDER *group,Item *having, ORDER *proc_param,
 	     ulong select_options, select_result *result, 
-	     SELECT_LEX_UNIT *unit, bool fake_select_lex)
+	     SELECT_LEX_UNIT *unit, SELECT_LEX *select_lex,
+	     bool fake_select_lex)
 {
   JOIN *join = new JOIN(thd, fields, select_options, result);
 
@@ -1013,7 +1011,7 @@ mysql_select(THD *thd, TABLE_LIST *tables, List<Item> &fields, COND *conds,
   thd->used_tables=0;                         // Updated by setup_fields
 
   if (join->prepare(tables, conds, order, group, having, proc_param,
-                  &(thd->lex.select_lex), unit, fake_select_lex))
+                  select_lex, unit, fake_select_lex))
   {
     DBUG_RETURN(-1);
   }
@@ -3087,11 +3085,6 @@ return_zero_rows(select_result *result,TABLE_LIST *tables,List<Item> &fields,
 {
   DBUG_ENTER("return_zero_rows");
 
-  if (select_options & SELECT_DESCRIBE)
-  {	
-    describe_info(current_thd, info);
-    DBUG_RETURN(0);
-  }
   if (procedure)
   {
     if (result->prepare(fields, unit))		// This hasn't been done yet
@@ -3725,6 +3718,7 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
   table->blob_ptr_size=mi_portable_sizeof_char_ptr;
   table->map=1;
   table->tmp_table= TMP_TABLE;
+  table->derived_select_number= 0;
   table->db_low_byte_first=1;			// True for HEAP and MyISAM
   table->temp_pool_slot = temp_pool_slot;
 
@@ -7139,7 +7133,6 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
   Item *item;
   List<Item> item_list;
   THD *thd=join->thd;
-  MYSQL_LOCK *save_lock;
   SELECT_LEX *select_lex = &(join->thd->lex.select_lex);
   select_result *result=join->result;
   DBUG_ENTER("select_describe");
@@ -7147,28 +7140,13 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
   /* Don't log this into the slow query log */
   select_lex->options&= ~(QUERY_NO_INDEX_USED | QUERY_NO_GOOD_INDEX_USED);
   join->unit->offset_limit_cnt= 0;
-  if (thd->lex.select == select_lex)
-  {
-    field_list.push_back(new Item_empty_string("table",NAME_LEN));
-    field_list.push_back(new Item_empty_string("type",10));
-    field_list.push_back(item=new Item_empty_string("possible_keys",
-						  NAME_LEN*MAX_KEY));
-    item->maybe_null=1;
-    field_list.push_back(item=new Item_empty_string("key",NAME_LEN));
-    item->maybe_null=1;
-    field_list.push_back(item=new Item_int("key_len",0,3));
-    item->maybe_null=1;
-    field_list.push_back(item=new Item_empty_string("ref",
-						    NAME_LEN*MAX_REF_PARTS));
-    item->maybe_null=1;
-    field_list.push_back(new Item_real("rows",0.0,0,10));
-    field_list.push_back(new Item_empty_string("Extra",255));
-    if (result->send_fields(field_list,1))
-      return;
-  }
 
   if (message)
   {
+    item_list.push_back(new Item_int((int)thd->lex.select->select_number));
+    item_list.push_back(new Item_string(thd->lex.select->type,
+					strlen(thd->lex.select->type),
+					default_charset_info));
     item_list.push_back(new Item_empty_string("",0));
     item_list.push_back(new Item_empty_string("",0));
     item_list.push_back(new Item_empty_string("",0));
@@ -7192,9 +7170,24 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
       String tmp1(buff1,sizeof(buff1),default_charset_info);
       String tmp2(buff2,sizeof(buff2),default_charset_info);
       item_list.empty();
+      item_list.push_back(new Item_int((int)thd->lex.select->select_number));
+      item_list.push_back(new Item_string(thd->lex.select->type,
+					  strlen(thd->lex.select->type),
+					  default_charset_info));
       if (tab->type == JT_ALL && tab->select && tab->select->quick)
 	tab->type= JT_RANGE;
-      item_list.push_back(new Item_string(table->table_name,strlen(table->table_name),default_charset_info));
+      if (table->tmp_table == TMP_TABLE && table->derived_select_number != 0)
+      {
+	// Derived table name generation
+	buff[512];
+	int len= my_snprintf(buff, 512, "<derived%u>",
+			     table->derived_select_number);
+	item_list.push_back(new Item_string(buff, len, default_charset_info));
+      }
+      else
+	item_list.push_back(new Item_string(table->table_name,
+					    strlen(table->table_name),
+					    default_charset_info));
       item_list.push_back(new Item_string(join_type_str[tab->type],strlen(join_type_str[tab->type]),default_charset_info));
       tmp1.length(0); tmp2.length(0);
       key_map bits;
@@ -7311,29 +7304,25 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
 	result->send_error(0,NullS);
     }
   }
-  if (!join->thd->lex.select->next_select())
-  {
-    save_lock=thd->lock;
-    thd->lock=(MYSQL_LOCK *)0;
-    result->send_eof();
-    thd->lock=save_lock;
-  }
   DBUG_VOID_RETURN;
 }
 
-
-static void describe_info(THD *thd, const char *info)
+int mysql_explain_select(THD *thd, SELECT_LEX *select_lex, char const *type, 
+			 select_result *result)
 {
-  List<Item> field_list;
-  String *packet= &thd->packet;
+  select_lex->type= type;
+  thd->lex.select= select_lex;
+  SELECT_LEX_UNIT *unit=  select_lex->master_unit();
+  int res= mysql_select(thd,(TABLE_LIST*) select_lex->table_list.first,
+			select_lex->item_list,
+			select_lex->where,
+			(ORDER*) select_lex->order_list.first,
+			(ORDER*) select_lex->group_list.first,
+			select_lex->having,
+			(ORDER*) thd->lex.proc_list.first,
+			select_lex->options | thd->options | SELECT_DESCRIBE,
+			result, unit, select_lex, 0);
 
-  /* Don't log this into the slow query log */
-  thd->lex.select_lex.options&= ~(QUERY_NO_INDEX_USED | QUERY_NO_GOOD_INDEX_USED);
-  field_list.push_back(new Item_empty_string("Comment",80));
-  if (send_fields(thd,field_list,1))
-    return; /* purecov: inspected */
-  packet->length(0);
-  net_store_data(packet,info);
-  if (!my_net_write(&thd->net,(char*) packet->ptr(),packet->length()))
-    send_eof(&thd->net);
+  return res;
 }
+  

sql/sql_union.cc

@@ -111,6 +111,7 @@ int st_select_lex_unit::prepare(THD *thd, select_result *result)
   DBUG_ENTER("st_select_lex_unit::prepare");
   this->thd= thd;
   this->result= result;
+  SELECT_LEX *lex_select_save= thd->lex.select;
 
   /* Global option */
   if (((void*)(global_parameters)) == ((void*)this))
@@ -148,9 +149,9 @@ int st_select_lex_unit::prepare(THD *thd, select_result *result)
     /* Create a list of items that will be in the result set */
     while ((item= it++))
       if (item_list.push_back(item))
-	DBUG_RETURN(-1);
+	goto err;
     if (setup_fields(thd,first_table,item_list,0,0,1))
-      DBUG_RETURN(-1);
+      goto err;
   }
 
   bzero((char*) &tmp_table_param,sizeof(tmp_table_param));
@@ -162,7 +163,7 @@ int st_select_lex_unit::prepare(THD *thd, select_result *result)
 				(first_select()->options | thd->options |
 				 TMP_TABLE_ALL_COLUMNS),
 				this)))
-    DBUG_RETURN(-1);
+    goto err;
   table->file->extra(HA_EXTRA_WRITE_CACHE);
   table->file->extra(HA_EXTRA_IGNORE_DUP_KEY);
   bzero((char*) &result_table_list,sizeof(result_table_list));
@@ -171,7 +172,7 @@ int st_select_lex_unit::prepare(THD *thd, select_result *result)
   result_table_list.table=table;
 
   if (!(union_result=new select_union(table)))
-    DBUG_RETURN(-1);
+    goto err;
 
   union_result->save_time_stamp=!describe;
   union_result->tmp_table_param=&tmp_table_param;
@@ -202,9 +203,13 @@ int st_select_lex_unit::prepare(THD *thd, select_result *result)
 		       (ORDER*) NULL,
 		       sl, this, 0);
     if (res | thd->fatal_error)
-      DBUG_RETURN(res | thd->fatal_error);
+      goto err;
   }
+  thd->lex.select= lex_select_save;
   DBUG_RETURN(res | thd->fatal_error);
+err:
+  thd->lex.select= lex_select_save;
+  DBUG_RETURN(-1);
 }
 
 int st_select_lex_unit::exec()
@@ -214,7 +219,7 @@ int st_select_lex_unit::exec()
   {
     if (optimized && item && item->assigned())
       item->assigned(0); // We will reinit & rexecute unit
-      
+    SELECT_LEX *lex_select_save= thd->lex.select;
     for (SELECT_LEX *sl= first_select(); sl; sl= sl->next_select())
     {
       thd->lex.select=sl;
@@ -234,8 +239,12 @@ int st_select_lex_unit::exec()
       res= sl->join->error;
 
       if (res)
+      {
+	thd->lex.select= lex_select_save;
 	DBUG_RETURN(res);
       }
+    }
+    thd->lex.select= lex_select_save;
     optimized= 1;
   }
 
@@ -283,7 +292,7 @@ int st_select_lex_unit::exec()
 			0: 
 			(ORDER*)global_parameters->order_list.first,
 			(ORDER*) NULL, NULL, (ORDER*) NULL,
-			thd->options, result, this, 1);
+			thd->options, result, this, first_select(), 1);
       if (found_rows_for_union && !res)
 	thd->limit_found_rows = (ulonglong)table->file->records;
     }

sql/table.h

@@ -128,6 +128,9 @@ struct st_table {
 
   uint          temp_pool_slot;
 
+  /* number of select if it is derived table */
+  uint          derived_select_number;   
+
   THD		*in_use;			/* Which thread uses this */
   struct st_table *next,*prev;
 };