From a24144636295d4f2a1d95477872c56c46e59bbff Mon Sep 17 00:00:00 2001
From: "evgen@moonbone.local" <>
Date: Sat, 10 Feb 2007 00:00:07 +0300
Subject: [PATCH] Bug#12122: The MERGE algorithm isn't applicable if the ORDER
 BY clause is present.

A view created with CREATE VIEW ... ORDER BY ... cannot be resolved with
the MERGE algorithm, even when no other part of the CREATE VIEW statement
would require the view to be resolved using the TEMPTABLE algorithm.

The check for presence of the ORDER BY clause in the underlying select is
removed from the st_lex::can_be_merged() function.
The ORDER BY list of the underlying select is appended to the ORDER BY list
---
 mysql-test/r/view.result | 39 +++++++++++++++++++++++++++++++++++++++
 mysql-test/t/view.test   | 14 ++++++++++++++
 sql/sql_lex.cc           |  1 -
 3 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/mysql-test/r/view.result b/mysql-test/r/view.result
index a52882fef2f..462916ec09b 100644
--- a/mysql-test/r/view.result
+++ b/mysql-test/r/view.result
@@ -3078,4 +3078,43 @@ b
 2
 DROP VIEW v1;
 DROP TABLE t1,t2;
+create table t1(f1 int, f2 int);
+insert into t1 values(1,2),(1,3),(1,1),(2,3),(2,1),(2,2);
+select * from t1;
+f1	f2
+1	2
+1	3
+1	1
+2	3
+2	1
+2	2
+create view v1 as select * from t1 order by f2;
+select * from v1;
+f1	f2
+1	1
+2	1
+1	2
+2	2
+1	3
+2	3
+explain extended select * from v1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	6	Using filesort
+Warnings:
+Note	1003	select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` order by `test`.`t1`.`f2`
+select * from v1 order by f1;
+f1	f2
+1	1
+1	2
+1	3
+2	1
+2	2
+2	3
+explain extended select * from v1 order by f1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	6	Using filesort
+Warnings:
+Note	1003	select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` order by `test`.`t1`.`f1`,`test`.`t1`.`f2`
+drop view v1;
+drop table t1;
 End of 5.0 tests.
diff --git a/mysql-test/t/view.test b/mysql-test/t/view.test
index 0fa5765bb64..7fdca1ff7e0 100644
--- a/mysql-test/t/view.test
+++ b/mysql-test/t/view.test
@@ -3024,4 +3024,18 @@ SELECT * FROM t2;
 DROP VIEW v1;
 DROP TABLE t1,t2;
 
+#
+# Bug#12122: Views with ORDER BY can't be resolved using MERGE algorithm.
+#
+create table t1(f1 int, f2 int);
+insert into t1 values(1,2),(1,3),(1,1),(2,3),(2,1),(2,2);
+select * from t1;
+create view v1 as select * from t1 order by f2;
+select * from v1;
+explain extended select * from v1;
+select * from v1 order by f1;
+explain extended select * from v1 order by f1;
+drop view v1;
+drop table t1;
+
 --echo End of 5.0 tests.
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index a362e6c7fd2..ce76c35b33c 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -1751,7 +1751,6 @@ bool st_lex::can_be_merged()
   }
 
   return (selects_allow_merge &&
-	  select_lex.order_list.elements == 0 &&
 	  select_lex.group_list.elements == 0 &&
 	  select_lex.having == 0 &&
           select_lex.with_sum_func == 0 &&