maria-developers team mailing list archive

[Sergey Petrunya <psergey@xxxxxxxxxxxx>]

At file:///home/psergey/dev/maria-5.3-subqueries-r7-rel/

------------------------------------------------------------
revno: 2777
revision-id: psergey@xxxxxxxxxxxx-20100315063254-z1ctm7srl0573s5c
parent: psergey@xxxxxxxxxxxx-20100314182543-4t3ehit7df20adu8
committer: Sergey Petrunya <psergey@xxxxxxxxxxxx>
branch nick: maria-5.3-subqueries-r7-rel
timestamp: Mon 2010-03-15 09:32:54 +0300
message:
  Apply fix by Roy Lyseng:
  Bug#48623: Multiple subqueries are optimized incorrectly
        
  The function setup_semijoin_dups_elimination() has a major loop that
  goes through every table in the JOIN object. Usually, there is a normal
  "plus one" increment in the for loop that implements this, but each semijoin
  nest is treated as one entity and there is another increment that skips past
  the semijoin nest to the next table in the JOIN object. However, when
  combining these two increments, the next joined table is skipped, and if that
  happens to be the start of another semijoin nest, the correct processing
  for that nest will not be carried out.
=== modified file 'mysql-test/r/subselect_sj.result'
--- a/mysql-test/r/subselect_sj.result	2010-03-14 18:25:43 +0000
+++ b/mysql-test/r/subselect_sj.result	2010-03-15 06:32:54 +0000
@@ -1079,3 +1079,36 @@
 partner_id
 partner2
 drop table t1,t2,t3,t4;
+# 
+# Bug#48623 Multiple subqueries are optimized incorrectly
+# 
+CREATE TABLE t1(val VARCHAR(10));
+CREATE TABLE t2(val VARCHAR(10));
+CREATE TABLE t3(val VARCHAR(10));
+INSERT INTO t1  VALUES('aaa'), ('bbb'), ('eee'), ('mmm'), ('ppp');
+INSERT INTO t2 VALUES('aaa'), ('aaa'), ('bbb'), ('eee'), ('mmm'), ('ppp');
+INSERT INTO t3 VALUES('aaa'), ('bbb'), ('eee'), ('mmm'), ('ppp');
+EXPLAIN
+SELECT *
+FROM t1
+WHERE t1.val IN (SELECT t2.val FROM t2
+WHERE  t2.val LIKE 'a%' OR t2.val LIKE 'e%')
+AND t1.val IN (SELECT t3.val FROM t3
+WHERE  t3.val LIKE 'a%' OR t3.val LIKE 'e%');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	5	Using where; FirstMatch(t1)
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; FirstMatch(t3)
+SELECT *
+FROM t1
+WHERE t1.val IN (SELECT t2.val FROM t2
+WHERE  t2.val LIKE 'a%' OR t2.val LIKE 'e%')
+AND t1.val IN (SELECT t3.val FROM t3
+WHERE  t3.val LIKE 'a%' OR t3.val LIKE 'e%');
+val
+aaa
+eee
+DROP TABLE t1;
+DROP TABLE t2;
+DROP TABLE t3;
+# End of Bug#48623

=== modified file 'mysql-test/r/subselect_sj_jcl6.result'
--- a/mysql-test/r/subselect_sj_jcl6.result	2010-03-14 18:25:43 +0000
+++ b/mysql-test/r/subselect_sj_jcl6.result	2010-03-15 06:32:54 +0000
@@ -1083,6 +1083,39 @@
 partner_id
 partner2
 drop table t1,t2,t3,t4;
+# 
+# Bug#48623 Multiple subqueries are optimized incorrectly
+# 
+CREATE TABLE t1(val VARCHAR(10));
+CREATE TABLE t2(val VARCHAR(10));
+CREATE TABLE t3(val VARCHAR(10));
+INSERT INTO t1  VALUES('aaa'), ('bbb'), ('eee'), ('mmm'), ('ppp');
+INSERT INTO t2 VALUES('aaa'), ('aaa'), ('bbb'), ('eee'), ('mmm'), ('ppp');
+INSERT INTO t3 VALUES('aaa'), ('bbb'), ('eee'), ('mmm'), ('ppp');
+EXPLAIN
+SELECT *
+FROM t1
+WHERE t1.val IN (SELECT t2.val FROM t2
+WHERE  t2.val LIKE 'a%' OR t2.val LIKE 'e%')
+AND t1.val IN (SELECT t3.val FROM t3
+WHERE  t3.val LIKE 'a%' OR t3.val LIKE 'e%');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	5	Using where; FirstMatch(t1); Using join buffer
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; FirstMatch(t3); Using join buffer
+SELECT *
+FROM t1
+WHERE t1.val IN (SELECT t2.val FROM t2
+WHERE  t2.val LIKE 'a%' OR t2.val LIKE 'e%')
+AND t1.val IN (SELECT t3.val FROM t3
+WHERE  t3.val LIKE 'a%' OR t3.val LIKE 'e%');
+val
+aaa
+eee
+DROP TABLE t1;
+DROP TABLE t2;
+DROP TABLE t3;
+# End of Bug#48623
 #
 # BUG#49129: Wrong result with IN-subquery with join_cache_level=6 and firstmatch=off
 #

=== modified file 'mysql-test/t/subselect_sj.test'
--- a/mysql-test/t/subselect_sj.test	2010-03-14 18:25:43 +0000
+++ b/mysql-test/t/subselect_sj.test	2010-03-15 06:32:54 +0000
@@ -943,5 +943,35 @@
 execute stmt;
 drop table t1,t2,t3,t4;
 
-
-
+--echo # 
+--echo # Bug#48623 Multiple subqueries are optimized incorrectly
+--echo # 
+
+CREATE TABLE t1(val VARCHAR(10));
+CREATE TABLE t2(val VARCHAR(10));
+CREATE TABLE t3(val VARCHAR(10));
+
+INSERT INTO t1  VALUES('aaa'), ('bbb'), ('eee'), ('mmm'), ('ppp');
+INSERT INTO t2 VALUES('aaa'), ('aaa'), ('bbb'), ('eee'), ('mmm'), ('ppp');
+INSERT INTO t3 VALUES('aaa'), ('bbb'), ('eee'), ('mmm'), ('ppp');
+
+EXPLAIN
+SELECT *
+FROM t1
+WHERE t1.val IN (SELECT t2.val FROM t2
+                 WHERE  t2.val LIKE 'a%' OR t2.val LIKE 'e%')
+  AND t1.val IN (SELECT t3.val FROM t3
+                 WHERE  t3.val LIKE 'a%' OR t3.val LIKE 'e%');
+
+SELECT *
+FROM t1
+WHERE t1.val IN (SELECT t2.val FROM t2
+                 WHERE  t2.val LIKE 'a%' OR t2.val LIKE 'e%')
+  AND t1.val IN (SELECT t3.val FROM t3
+                 WHERE  t3.val LIKE 'a%' OR t3.val LIKE 'e%');
+
+DROP TABLE t1;
+DROP TABLE t2;
+DROP TABLE t3;
+
+--echo # End of Bug#48623

=== modified file 'sql/opt_subselect.cc'
--- a/sql/opt_subselect.cc	2010-03-14 18:25:43 +0000
+++ b/sql/opt_subselect.cc	2010-03-15 06:32:54 +0000
@@ -3030,7 +3030,7 @@
   THD *thd= join->thd;
   DBUG_ENTER("setup_semijoin_dups_elimination");
 
-  for (i= join->const_tables ; i < join->tables ; i++)
+  for (i= join->const_tables ; i < join->tables; )
   {
     JOIN_TAB *tab=join->join_tab + i;
     POSITION *pos= join->best_positions + i;
@@ -3039,7 +3039,7 @@
       case SJ_OPT_MATERIALIZE:
       case SJ_OPT_MATERIALIZE_SCAN:
         /* Do nothing */
-        i += pos->n_sj_tables;
+        i+= pos->n_sj_tables;
         break;
       case SJ_OPT_LOOSE_SCAN:
       {
@@ -3055,7 +3055,7 @@
         tab->loosescan_key_len= keylen;
         if (pos->n_sj_tables > 1) 
           tab[pos->n_sj_tables - 1].do_firstmatch= tab;
-        i += pos->n_sj_tables;
+        i+= pos->n_sj_tables;
         break;
       }
       case SJ_OPT_DUPS_WEEDOUT:
@@ -3152,7 +3152,7 @@
         join->join_tab[first_table].flush_weedout_table= sjtbl;
         join->join_tab[i + pos->n_sj_tables - 1].check_weed_out_table= sjtbl;
 
-        i += pos->n_sj_tables;
+        i+= pos->n_sj_tables;
         break;
       }
       case SJ_OPT_FIRST_MATCH:
@@ -3174,10 +3174,11 @@
           }
         }
         j[-1].do_firstmatch= jump_to;
-        i += pos->n_sj_tables;
+        i+= pos->n_sj_tables;
         break;
       }
       case SJ_OPT_NONE:
+        i++;
         break;
     }
   }