MWL#17: Table elimination

- Correctly handle the case where we have multi-table DELETE and a table
  that we're deleting from looks like it could be eliminated.

1 files changed, 29 insertions, 0 deletions

diff --git a/mysql-test/r/table_elim.result b/mysql-test/r/table_elim.result
index 5aad6ea45bd..8ce03b06cab 100644
--- a/mysql-test/r/table_elim.result
+++ b/mysql-test/r/table_elim.result
@@ -278,3 +278,32 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	index	NULL	PRIMARY	10	NULL	2	Using index
 1	SIMPLE	t2	ref	a	a	3	test.t1.a	2	
 drop table t1, t2;
+#
+# check UPDATE/DELETE that look like they could be eliminated
+#
+create table t1 (a int primary key, b int);
+insert into t1 values (1,1),(2,2),(3,3);
+create table t2 like t1;
+insert into t2 select * from t1;
+update t1 left join t2 using (a) set t2.a=t2.a+100;
+select * from t1;
+a	b
+1	1
+2	2
+3	3
+select * from t2;
+a	b
+101	1
+102	2
+103	3
+delete from t2;
+insert into t2 select * from t1;
+delete t2 from t1 left join t2 using (a);
+select * from t1;
+a	b
+1	1
+2	2
+3	3
+select * from t2;
+a	b
+drop table t1, t2;