From 45503698c13c55a6c21e02f4422bd3a4bcb02fd9 Mon Sep 17 00:00:00 2001
From: Sergey Petrunya <psergey@askmonty.org>
Date: Thu, 21 Jun 2012 22:15:13 +0400
Subject: [PATCH] Test that SHOW EXPLAIN will print 'Distinct'.

---
 mysql-test/r/show_explain.result | 33 +++++++++++++++++++++++++++++++
 mysql-test/t/show_explain.test   | 34 ++++++++++++++++++++++++++++++--
 2 files changed, 65 insertions(+), 2 deletions(-)

diff --git a/mysql-test/r/show_explain.result b/mysql-test/r/show_explain.result
index 1c18112a7e5..07bcb29a7ea 100644
--- a/mysql-test/r/show_explain.result
+++ b/mysql-test/r/show_explain.result
@@ -695,4 +695,37 @@ WHERE a < ALL ( SELECT b FROM t1, t2 WHERE a = b )
 a	b
 set debug_dbug='';
 DROP TABLE t1, t2;
+# 
+#  Test that SHOW EXPLAIN will print 'Distinct'.
+#
+CREATE TABLE t1 (a int(10) unsigned not null primary key,b int(10) unsigned);
+INSERT INTO t1 VALUES (1,1),(2,1),(3,1),(4,1);
+CREATE TABLE t3 (a int(10) unsigned, key(A), b text);
+INSERT INTO t3 VALUES (1,'1'),(2,'2');
+create temporary table t4 select * from t3;
+insert into t3 select * from t4;
+insert into t4 select * from t3;
+insert into t3 select * from t4;
+insert into t4 select * from t3;
+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;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	PRIMARY	PRIMARY	4	NULL	4	Using index; Using temporary
+1	SIMPLE	t3	ref	a	a	5	test.t1.a	7	Using index; Distinct
+set @show_explain_probe_select_id=1;
+set debug_dbug='d,show_explain_probe_join_exec_start';
+select distinct t1.a from t1,t3 where t1.a=t3.a;
+show explain for $thr2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	PRIMARY	PRIMARY	4	NULL	4	Using index; Using temporary
+1	SIMPLE	t3	ref	a	a	5	test.t1.a	7	Using index; Distinct
+Warnings:
+Note	1003	select distinct t1.a from t1,t3 where t1.a=t3.a
+a
+1
+2
+set debug_dbug='';
+drop table t1,t3,t4;
 drop table t0;
diff --git a/mysql-test/t/show_explain.test b/mysql-test/t/show_explain.test
index d7e5a0bc6fd..ffd2c25dfd9 100644
--- a/mysql-test/t/show_explain.test
+++ b/mysql-test/t/show_explain.test
@@ -692,11 +692,41 @@ evalp show explain for $thr2;
 
 connection con1;
 reap;
-
 set debug_dbug='';
-
 DROP TABLE t1, t2;
 
+--echo # 
+--echo #  Test that SHOW EXPLAIN will print 'Distinct'.
+--echo #
+CREATE TABLE t1 (a int(10) unsigned not null primary key,b int(10) unsigned);
+INSERT INTO t1 VALUES (1,1),(2,1),(3,1),(4,1);
+
+CREATE TABLE t3 (a int(10) unsigned, key(A), b text);
+INSERT INTO t3 VALUES (1,'1'),(2,'2');
+
+create temporary table t4 select * from t3;
+insert into t3 select * from t4;
+insert into t4 select * from t3;
+insert into t3 select * from t4;
+insert into t4 select * from t3;
+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;
+
+set @show_explain_probe_select_id=1;
+set debug_dbug='d,show_explain_probe_join_exec_start';
+--send
+select distinct t1.a from t1,t3 where t1.a=t3.a;
+connection default;
+--source include/wait_condition.inc
+evalp show explain for $thr2;
+
+connection con1;
+reap;
+set debug_dbug='';
+
+drop table t1,t3,t4;
 ## TODO: Test this: have several SHOW EXPLAIN requests be queued up for a
 ##       thread and served together.