Make EXPLAIN better at displaying MRR/BKA:

- "Using MRR" is no longer shown with range access.
- Instead, both range and BKA accesses will show one of the following:
  = "Rowid-ordered scan"
  = "Key-ordered scan"
  = "Key-ordered Rowid-ordered scan"
depending on whether DS-MRR implementation will do scan keys in order, rowids in order,
or both.
- The patch also introduces a way for other storage engines/MRR implementations to
  pass information to EXPLAIN output about the properties of employed MRR scans.

1 files changed, 26 insertions, 26 deletions

diff --git a/mysql-test/r/func_in.result b/mysql-test/r/func_in.result
index 3ca4d9c2da5..f65255b272f 100644
--- a/mysql-test/r/func_in.result
+++ b/mysql-test/r/func_in.result
@@ -241,7 +241,7 @@ insert into t2 select C.a*2+1, 'yes' from t1 C;
 explain 
 select * from t2 where a NOT IN (0, 2,4,6,8,10,12,14,16,18);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	5	NULL	12	Using index condition; Using MRR
+1	SIMPLE	t2	range	a	a	5	NULL	12	Using index condition; Rowid-ordered scan
 select * from t2 where a NOT IN (0, 2,4,6,8,10,12,14,16,18);
 a	filler
 1	yes
@@ -256,10 +256,10 @@ a	filler
 19	yes
 explain select * from t2 force index(a) where a NOT IN (2,2,2,2,2,2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	5	NULL	912	Using index condition; Using MRR
+1	SIMPLE	t2	range	a	a	5	NULL	912	Using index condition; Rowid-ordered scan
 explain select * from t2 force index(a) where a <> 2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	5	NULL	912	Using index condition; Using MRR
+1	SIMPLE	t2	range	a	a	5	NULL	912	Using index condition; Rowid-ordered scan
 drop table t2;
 create table t2 (a datetime, filler char(200), key(a));
 insert into t2 select '2006-04-25 10:00:00' + interval C.a minute,
@@ -271,7 +271,7 @@ select * from t2 where a NOT IN (
 '2006-04-25 10:00:00','2006-04-25 10:02:00','2006-04-25 10:04:00', 
 '2006-04-25 10:06:00', '2006-04-25 10:08:00');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	9	NULL	18	Using index condition; Using MRR
+1	SIMPLE	t2	range	a	a	9	NULL	18	Using index condition; Rowid-ordered scan
 select * from t2 where a NOT IN (
 '2006-04-25 10:00:00','2006-04-25 10:02:00','2006-04-25 10:04:00', 
 '2006-04-25 10:06:00', '2006-04-25 10:08:00');
@@ -295,7 +295,7 @@ insert into t2 values ('fon', '1'), ('fop','1'), ('barbaq','1'),
 ('barbas','1'), ('bazbazbay', '1'),('zz','1');
 explain select * from t2 where a not in('foo','barbar', 'bazbazbaz');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	13	NULL	7	Using index condition; Using MRR
+1	SIMPLE	t2	range	a	a	13	NULL	7	Using index condition; Rowid-ordered scan
 drop table t2;
 create table t2 (a decimal(10,5), filler char(200), key(a));
 insert into t2 select 345.67890, 'no' from t1 A, t1 B;
@@ -306,7 +306,7 @@ insert into t2 values (0, '1'), (22334.123,'1'), (33333,'1'),
 explain
 select * from t2 where a not in (345.67890, 43245.34, 64224.56344);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	7	NULL	7	Using index condition; Using MRR
+1	SIMPLE	t2	range	a	a	7	NULL	7	Using index condition; Rowid-ordered scan
 select * from t2 where a not in (345.67890, 43245.34, 64224.56344);
 a	filler
 0.00000	1
@@ -630,16 +630,16 @@ INSERT INTO t1 (c_int) SELECT 0 FROM t1;
 INSERT INTO t1 (c_int) SELECT 0 FROM t1;
 EXPLAIN SELECT * FROM t1 WHERE c_int IN (1, 2, 3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_int	c_int	4	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_int	c_int	4	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_int IN (NULL, 1, 2, 3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_int	c_int	4	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_int	c_int	4	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_int IN (1, 2, 3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_int	c_int	4	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_int	c_int	4	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_int IN (1, NULL, 2, NULL, 3, NULL);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_int	c_int	4	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_int	c_int	4	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_int IN (NULL);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
@@ -648,10 +648,10 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (1, 2, 3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_decimal	c_decimal	3	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_decimal	c_decimal	3	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (NULL, 1, 2, 3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_decimal	c_decimal	3	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_decimal	c_decimal	3	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (NULL);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
@@ -660,10 +660,10 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 EXPLAIN SELECT * FROM t1 WHERE c_float IN (1, 2, 3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_float	c_float	4	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_float	c_float	4	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_float IN (NULL, 1, 2, 3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_float	c_float	4	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_float	c_float	4	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_float IN (NULL);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
@@ -672,10 +672,10 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 EXPLAIN SELECT * FROM t1 WHERE c_bit IN (1, 2, 3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_bit	c_bit	2	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_bit	c_bit	2	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_bit IN (NULL, 1, 2, 3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_bit	c_bit	2	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_bit	c_bit	2	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_bit IN (NULL);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
@@ -685,11 +685,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT * FROM t1 WHERE c_date 
 IN ('2009-09-01', '2009-09-02', '2009-09-03');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_date	c_date	3	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_date	c_date	3	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_date
 IN (NULL, '2009-09-01', '2009-09-02', '2009-09-03');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_date	c_date	3	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_date	c_date	3	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_date IN (NULL);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
@@ -699,11 +699,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT * FROM t1 WHERE c_datetime
 IN ('2009-09-01 00:00:01', '2009-09-02 00:00:01', '2009-09-03 00:00:01');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_datetime	c_datetime	8	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_datetime	c_datetime	8	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_datetime
 IN (NULL, '2009-09-01 00:00:01', '2009-09-02 00:00:01', '2009-09-03 00:00:01');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_datetime	c_datetime	8	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_datetime	c_datetime	8	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_datetime IN (NULL);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
@@ -713,11 +713,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT * FROM t1 WHERE c_timestamp
 IN ('2009-09-01 00:00:01', '2009-09-01 00:00:02', '2009-09-01 00:00:03');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_timestamp	c_timestamp	4	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_timestamp	c_timestamp	4	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_timestamp
 IN (NULL, '2009-09-01 00:00:01', '2009-09-01 00:00:02', '2009-09-01 00:00:03');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_timestamp	c_timestamp	4	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_timestamp	c_timestamp	4	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_timestamp IN (NULL);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
@@ -726,10 +726,10 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 EXPLAIN SELECT * FROM t1 WHERE c_year IN (1, 2, 3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_year	c_year	1	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_year	c_year	1	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_year IN (NULL, 1, 2, 3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_year	c_year	1	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_year	c_year	1	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_year IN (NULL);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
@@ -738,10 +738,10 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 EXPLAIN SELECT * FROM t1 WHERE c_char IN ('1', '2', '3');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_char	c_char	10	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_char	c_char	10	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_char IN (NULL, '1', '2', '3');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c_char	c_char	10	NULL	3	Using index condition; Using MRR
+1	SIMPLE	t1	range	c_char	c_char	10	NULL	3	Using index condition; Rowid-ordered scan
 EXPLAIN SELECT * FROM t1 WHERE c_char IN (NULL);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables