Merge magare.gmz:/home/kgeorge/mysql/work/B30788-5.0-opt

into  magare.gmz:/home/kgeorge/mysql/work/B30788-5.1-opt


mysql-test/r/subselect3.result:
  Auto merged
sql/item.h:
  Auto merged
sql/sql_select.cc:
  Auto merged
mysql-test/r/subselect.result:
  merge of bug 30788 to 5.1-opt
mysql-test/t/subselect.test:
  merge of bug 30788 to 5.1-opt

mysql-test/r/subselect.result

@@ -1307,7 +1307,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	4	100.00	Using where; Using index
 2	DEPENDENT SUBQUERY	t1	unique_subquery	PRIMARY	PRIMARY	4	func	1	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<primary_index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on PRIMARY where (`test`.`t1`.`b` <> 30))))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<primary_index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on PRIMARY where ((`test`.`t1`.`b` <> 30) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`)))))
 select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
 a
 2
@@ -1316,7 +1316,7 @@ explain extended select * from t2 where t2.a in (select t1.a from t1,t3 where t1
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	4	100.00	Using where; Using index
 2	DEPENDENT SUBQUERY	t1	eq_ref	PRIMARY	PRIMARY	4	func	1	100.00	Using where
-2	DEPENDENT SUBQUERY	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.b	1	100.00	Using where; Using index
+2	DEPENDENT SUBQUERY	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.b	1	100.00	Using index
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(select 1 AS `Not_used` from `test`.`t1` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t1`.`b`) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`))))
 drop table t1, t2, t3;
@@ -1334,9 +1334,9 @@ a
 explain extended select * from t2 where t2.a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	NULL	a	5	NULL	4	100.00	Using where; Using index
-2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	5	func	1001	100.00	Using index
+2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	5	func	1001	100.00	Using index; Using where
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a)))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a where (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`))))
 select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
 a
 2
@@ -1346,7 +1346,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	NULL	a	5	NULL	4	100.00	Using where; Using index
 2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	5	func	1001	100.00	Using index; Using where
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a where (`test`.`t1`.`b` <> 30))))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a where ((`test`.`t1`.`b` <> 30) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`)))))
 select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
 a
 2
@@ -1373,7 +1373,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	NULL	a	5	NULL	4	100.00	Using where; Using index
 2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	5	func	1001	100.00	Using index; Using where
 Warnings:
-Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a where (`test`.`t1`.`b` <> 30))))
+Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a where ((`test`.`t1`.`b` <> 30) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`)))))
 drop table t1, t2, t3;
 create table t1 (a int, b int);
 create table t2 (a int, b int);
@@ -1737,7 +1737,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	12	100.00	Using where
 2	DEPENDENT SUBQUERY	t1	unique_subquery	PRIMARY	PRIMARY	4	func	1	100.00	Using index; Using where
 Warnings:
-Note	1003	select `test`.`t1`.`id` AS `id`,`test`.`t1`.`text` AS `text` from `test`.`t1` where (not(<in_optimizer>(`test`.`t1`.`id`,<exists>(<primary_index_lookup>(<cache>(`test`.`t1`.`id`) in t1 on PRIMARY where (`test`.`t1`.`id` < 8))))))
+Note	1003	select `test`.`t1`.`id` AS `id`,`test`.`t1`.`text` AS `text` from `test`.`t1` where (not(<in_optimizer>(`test`.`t1`.`id`,<exists>(<primary_index_lookup>(<cache>(`test`.`t1`.`id`) in t1 on PRIMARY where ((`test`.`t1`.`id` < 8) and (<cache>(`test`.`t1`.`id`) = `test`.`t1`.`id`)))))))
 explain extended select * from t1 as tt where not exists (select id from t1 where id < 8 and (id = tt.id or id is null) having id is not null);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	tt	ALL	NULL	NULL	NULL	NULL	12	100.00	Using where
@@ -4199,6 +4199,37 @@ LEFT(t1.a1,1)
 SELECT a2 FROM t2 WHERE t2.a2 IN (SELECT t1.a1 FROM t1,t3 WHERE t1.b1=t3.a3);
 a2
 DROP TABLE t1, t2, t3;
+CREATE TABLE t1 (a CHAR(1), b VARCHAR(10));
+INSERT INTO t1 VALUES ('a', 'aa');
+INSERT INTO t1 VALUES ('a', 'aaa');
+SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
+a	b
+CREATE INDEX I1 ON t1 (a);
+CREATE INDEX I2 ON t1 (b);
+EXPLAIN SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t1	index_subquery	I1	I1	2	func	2	Using index; Using where
+SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
+a	b
+CREATE TABLE t2 (a VARCHAR(1), b VARCHAR(10));
+INSERT INTO t2 SELECT * FROM t1;
+CREATE INDEX I1 ON t2 (a);
+CREATE INDEX I2 ON t2 (b);
+EXPLAIN SELECT a,b FROM t2 WHERE b IN (SELECT a FROM t2);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t2	index_subquery	I1	I1	4	func	2	Using index; Using where
+SELECT a,b FROM t2 WHERE b IN (SELECT a FROM t2);
+a	b
+EXPLAIN
+SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1 WHERE LENGTH(a)<500);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+2	DEPENDENT SUBQUERY	t1	index_subquery	I1	I1	2	func	2	Using index; Using where
+SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1 WHERE LENGTH(a)<500);
+a	b
+DROP TABLE t1,t2;
 End of 5.0 tests.
 CREATE TABLE t1 (a int, b int);
 INSERT INTO t1 VALUES (2,22),(1,11),(2,22);

mysql-test/r/subselect3.result

@@ -757,6 +757,6 @@ a
 EXPLAIN SELECT a FROM t1 WHERE a NOT IN (SELECT a FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where
-2	DEPENDENT SUBQUERY	t2	unique_subquery	PRIMARY	PRIMARY	4	func	1	Using index
+2	DEPENDENT SUBQUERY	t2	unique_subquery	PRIMARY	PRIMARY	4	func	1	Using index; Using where
 DROP TABLE t1;
 End of 5.0 tests

mysql-test/t/subselect.test

@@ -3044,6 +3044,31 @@ SELECT LEFT(t1.a1,1) FROM t1,t3 WHERE t1.b1=t3.a3;
 SELECT a2 FROM t2 WHERE t2.a2 IN (SELECT t1.a1 FROM t1,t3 WHERE t1.b1=t3.a3);
 DROP TABLE t1, t2, t3;
 
+#
+# Bug #30788: Inconsistent retrieval of char/varchar
+#
+
+CREATE TABLE t1 (a CHAR(1), b VARCHAR(10));
+INSERT INTO t1 VALUES ('a', 'aa');
+INSERT INTO t1 VALUES ('a', 'aaa');
+SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
+CREATE INDEX I1 ON t1 (a);
+CREATE INDEX I2 ON t1 (b);
+EXPLAIN SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
+SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
+
+CREATE TABLE t2 (a VARCHAR(1), b VARCHAR(10));
+INSERT INTO t2 SELECT * FROM t1;
+CREATE INDEX I1 ON t2 (a);
+CREATE INDEX I2 ON t2 (b);
+EXPLAIN SELECT a,b FROM t2 WHERE b IN (SELECT a FROM t2);
+SELECT a,b FROM t2 WHERE b IN (SELECT a FROM t2);
+EXPLAIN
+SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1 WHERE LENGTH(a)<500);
+SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1 WHERE LENGTH(a)<500);
+
+DROP TABLE t1,t2;
+
 --echo End of 5.0 tests.
 
 #

sql/item.h

@@ -2620,8 +2620,18 @@ class Item_cache: public Item
 protected:
   Item *example;
   table_map used_table_map;
+  /*
+    Field that this object will get value from. This is set/used by 
+    index-based subquery engines to detect and remove the equality injected 
+    by IN->EXISTS transformation.
+    For all other uses of Item_cache, cached_field doesn't matter.
+  */  
+  Field *cached_field;
 public:
-  Item_cache(): example(0), used_table_map(0) {fixed= 1; null_value= 1;}
+  Item_cache(): example(0), used_table_map(0), cached_field(0) 
+  {
+    fixed= 1; null_value= 1;
+  }
 
   void set_used_tables(table_map map) { used_table_map= map; }
 
@@ -2633,6 +2643,8 @@ class Item_cache: public Item
     decimals= item->decimals;
     collation.set(item->collation);
     unsigned_flag= item->unsigned_flag;
+    if (item->type() == FIELD_ITEM)
+      cached_field= ((Item_field *)item)->field;
     return 0;
   };
   virtual void store(Item *)= 0;
@@ -2643,6 +2655,14 @@ class Item_cache: public Item
   // to prevent drop fixed flag (no need parent cleanup call)
   void cleanup() {}
   void print(String *str);
+  bool eq_def(Field *field) 
+  { 
+    return cached_field ? cached_field->eq_def (field) : FALSE;
+  }
+  bool eq(const Item *item, bool binary_cmp) const
+  {
+    return this == item;
+  }
 };
 
 

sql/sql_select.cc

@@ -223,6 +223,7 @@ static void select_describe(JOIN *join, bool need_tmp_table,bool need_order,
 			    bool distinct, const char *message=NullS);
 static Item *remove_additional_cond(Item* conds);
 static void add_group_and_distinct_keys(JOIN *join, JOIN_TAB *join_tab);
+static bool test_if_ref(Item_field *left_item,Item *right_item);
 
 
 /*
@@ -680,9 +681,6 @@ JOIN::prepare(Item ***rref_pointer_array,
     without "checking NULL", remove the predicates that were pushed down
     into the subquery.
 
-    We can remove the equalities that will be guaranteed to be true by the
-    fact that subquery engine will be using index lookup.
-
     If the subquery compares scalar values, we can remove the condition that
     was wrapped into trig_cond (it will be checked when needed by the subquery
     engine)
@@ -692,6 +690,12 @@ JOIN::prepare(Item ***rref_pointer_array,
     and non-NULL values, we'll do a full table scan and will rely on the
     equalities corresponding to non-NULL parts of left tuple to filter out
     non-matching records.
+
+    TODO: We can remove the equalities that will be guaranteed to be true by the
+    fact that subquery engine will be using index lookup. This must be done only
+    for cases where there are no conversion errors of significance, e.g. 257
+    that is searched in a byte. But this requires homogenization of the return 
+    codes of all Field*::store() methods.
 */
 
 void JOIN::remove_subq_pushed_predicates(Item **where)
@@ -699,17 +703,13 @@ void JOIN::remove_subq_pushed_predicates(Item **where)
   if (conds->type() == Item::FUNC_ITEM &&
       ((Item_func *)this->conds)->functype() == Item_func::EQ_FUNC &&
       ((Item_func *)conds)->arguments()[0]->type() == Item::REF_ITEM &&
-      ((Item_func *)conds)->arguments()[1]->type() == Item::FIELD_ITEM)
+      ((Item_func *)conds)->arguments()[1]->type() == Item::FIELD_ITEM &&
+      test_if_ref ((Item_field *)((Item_func *)conds)->arguments()[1],
+                   ((Item_func *)conds)->arguments()[0]))
   {
     *where= 0;
     return;
   }
-  if (conds->type() == Item::COND_ITEM &&
-      ((class Item_func *)this->conds)->functype() ==
-      Item_func::COND_AND_FUNC)
-  {
-    *where= remove_additional_cond(conds);
-  }
 }
 
 
@@ -1259,7 +1259,7 @@ JOIN::optimize()
   {
     if (!having)
     {
-      Item *where= 0;
+      Item *where= conds;
       if (join_tab[0].type == JT_EQ_REF &&
 	  join_tab[0].ref.items[0]->name == in_left_expr_name)
       {
@@ -12206,8 +12206,12 @@ static bool test_if_ref(Item_field *left_item,Item *right_item)
     Item *ref_item=part_of_refkey(field->table,field);
     if (ref_item && ref_item->eq(right_item,1))
     {
+      right_item= right_item->real_item();
       if (right_item->type() == Item::FIELD_ITEM)
 	return (field->eq_def(((Item_field *) right_item)->field));
+      /* remove equalities injected by IN->EXISTS transformation */
+      else if (right_item->type() == Item::CACHE_ITEM)
+        return ((Item_cache *)right_item)->eq_def (field);
       if (right_item->const_item() && !(right_item->is_null()))
       {
 	/*