bk commit into 5.0 tree (sergefp:1.2456) BUG#27939

[Sergey Petrunia]

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5.0 repository of psergey. When psergey does a push these changes will
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ChangeSet@stripped, 2007-04-19 03:04:23+04:00, sergefp@stripped +3 -0
  BUG#27939: Early NULLs filtering doesn't work for eq_ref access
   - Turn it on for JT_EQ_REF access method

  mysql-test/r/join.result@stripped, 2007-04-19 03:04:20+04:00, sergefp@stripped +28 -0
    BUG#27939: Testcase

  mysql-test/t/join.test@stripped, 2007-04-19 03:04:20+04:00, sergefp@stripped +23 -0
    BUG#27939: Testcase

  sql/sql_select.cc@stripped, 2007-04-19 03:04:20+04:00, sergefp@stripped +3 -2
    BUG#27939: Early NULLs filtering doesn't work for eq_ref access
     - Turn it on for JT_EQ_REF access method

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	sergefp
# Host:	pylon64.mylan
# Root:	/home/psergey/mysql-5.0-bug27870-review

--- 1.509/sql/sql_select.cc	2007-04-19 03:04:30 +04:00
+++ 1.510/sql/sql_select.cc	2007-04-19 03:04:30 +04:00
@@ -5444,8 +5444,9 @@
   for (uint i=join->const_tables ; i < join->tables ; i++)
   {
     JOIN_TAB *tab=join->join_tab+i;
-    if ((tab->type == JT_REF || tab->type == JT_REF_OR_NULL) &&
-         !tab->table->maybe_null)
+    if ((tab->type == JT_REF || tab->type == JT_EQ_REF || 
+         tab->type == JT_REF_OR_NULL) &&
+        !tab->table->maybe_null)
     {
       for (uint keypart= 0; keypart < tab->ref.key_parts; keypart++)
       {

--- 1.41/mysql-test/r/join.result	2007-04-19 03:04:30 +04:00
+++ 1.42/mysql-test/r/join.result	2007-04-19 03:04:30 +04:00
@@ -779,4 +779,32 @@
 Name	varchar(50)	YES		NULL	
 DROP VIEW v1;
 DROP TABLE t1,t2,tv1,tv2;
+create table t1 (a int, b int);
+insert into t1 values 
+(NULL, 1),
+(NULL, 2),
+(NULL, 3),
+(NULL, 4);
+create table t2 (a int not null, primary key(a));
+insert into t2 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+create table t3 (a int not null, primary key(a));
+insert into t3 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+flush status;
+select * from t1, t2, t3 where t3.a=t1.a and t2.a=t1.b;
+a	b	a	a
+explain select * from t1, t2, t3 where t3.a=t1.a and t2.a=t1.b;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	
+1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.b	1	Using index
+1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.a	1	Using index
+We expect rnd_next=5, and read_key must be 0 because of short-cutting:
+show status like 'Handler_read%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	0
+Handler_read_next	0
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_next	5
+drop table t1, t2, t3;
 End of 5.0 tests.

--- 1.35/mysql-test/t/join.test	2007-04-19 03:04:30 +04:00
+++ 1.36/mysql-test/t/join.test	2007-04-19 03:04:30 +04:00
@@ -610,4 +610,27 @@
 DROP VIEW v1;
 DROP TABLE t1,t2,tv1,tv2;
 
+
+# BUG#27939: Early NULLs filtering doesn't work for eq_ref access
+create table t1 (a int, b int);
+insert into t1 values 
+  (NULL, 1),
+  (NULL, 2),
+  (NULL, 3),
+  (NULL, 4);
+
+create table t2 (a int not null, primary key(a));
+insert into t2 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+
+create table t3 (a int not null, primary key(a));
+insert into t3 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+
+flush status;
+select * from t1, t2, t3 where t3.a=t1.a and t2.a=t1.b;
+explain select * from t1, t2, t3 where t3.a=t1.a and t2.a=t1.b;
+--echo We expect rnd_next=5, and read_key must be 0 because of short-cutting:
+show status like 'Handler_read%'; 
+drop table t1, t2, t3;
+
+
 --echo End of 5.0 tests.