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From:Sergey Petrunia Date:April 22 2005 8:13pm
Subject:bk commit into 5.0 tree (sergefp:1.1863) BUG#8490
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Below is the list of changes that have just been committed into a local
5.0 repository of psergey. When psergey does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet
  1.1863 05/04/23 00:13:46 sergefp@stripped +3 -0
  Fix for BUG#8490: In mysql_make_view for join algorithm views we need 
  to insert view's subqueries into select_lex->slave(->next)* chain. 
  In case a join has several such views, don't add the same subqueries several times
  (this forms a loop on the above chain which breaks many parts of the code)

  sql/sql_view.cc
    1.42 05/04/23 00:13:42 sergefp@stripped +11 -3
    Fix for BUG#8490: In mysql_make_view for join algorithm views we need 
    to insert view's subqueries into select_lex->slave(->next)* chain. 
    In case a join has several such views, don't add the same subqueries several times
    (this forms a loop on the above chain which breaks many parts of the code)

  mysql-test/t/view.test
    1.67 05/04/23 00:13:42 sergefp@stripped +14 -0
    Testcase for BUG#8490

  mysql-test/r/view.result
    1.78 05/04/23 00:13:42 sergefp@stripped +18 -0
    Testcase for BUG#8490

# 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:	newbox.mylan
# Root:	/home/psergey/mysql-5.0-bug8490-2

--- 1.77/mysql-test/r/view.result	2005-04-19 01:43:23 +04:00
+++ 1.78/mysql-test/r/view.result	2005-04-23 00:13:42 +04:00
@@ -1694,3 +1694,21 @@
 5	david	NULL	NULL
 DROP VIEW v1,v2,v3;
 DROP TABLE t1,t2;
+create table t1 as select 1 A union select 2 union select 3;
+create table t2 as select * from t1;
+create view v1 as select * from t1 where a in (select * from t2);
+select * from v1 A, v1 B where A.a = B.a;
+A	A
+1	1
+2	2
+3	3
+create table t3 as select a a,a b from t2;
+create view v2 as select * from t3 where 
+a in (select * from t1) or b in (select * from t2);
+select * from v2 A, v2 B where A.a = B.b;
+a	b	a	b
+1	1	1	1
+2	2	2	2
+3	3	3	3
+drop view v1, v2;
+drop table t1, t2, t3;

--- 1.66/mysql-test/t/view.test	2005-04-14 10:01:24 +04:00
+++ 1.67/mysql-test/t/view.test	2005-04-23 00:13:42 +04:00
@@ -1519,3 +1519,17 @@
  
 DROP VIEW v1,v2,v3;
 DROP TABLE t1,t2;
+
+# BUG#8490 Select from views containing subqueries causes server to hang 
+# forever.
+create table t1 as select 1 A union select 2 union select 3;
+create table t2 as select * from t1;
+create view v1 as select * from t1 where a in (select * from t2);
+select * from v1 A, v1 B where A.a = B.a;
+create table t3 as select a a,a b from t2;
+create view v2 as select * from t3 where 
+  a in (select * from t1) or b in (select * from t2);
+select * from v2 A, v2 B where A.a = B.b;
+drop view v1, v2;
+drop table t1, t2, t3;
+

--- 1.41/sql/sql_view.cc	2005-04-03 16:30:12 +04:00
+++ 1.42/sql/sql_view.cc	2005-04-23 00:13:42 +04:00
@@ -796,17 +796,25 @@
 
       /* Store WHERE clause for post-processing in setup_ancestor */
       table->where= view_select->where;
-
       /*
-        Add subqueries units to SELECT in which we merging current view.
-
+        Add subqueries units to SELECT into which we merging current view.
+        
+        unit(->next)* chain starts with subqueries that are used by this
+        view and continues with subqueries that are used by other views.
+        We must not add any subquery twice (otherwise we'll form a loop),
+        to do this we remember in end_unit the first subquery that has 
+        been already added.
+                
         NOTE: we do not support UNION here, so we take only one select
       */
+      SELECT_LEX_NODE *end_unit= table->select_lex->slave;
       for (SELECT_LEX_UNIT *unit= lex->select_lex.first_inner_unit();
            unit;
            unit= unit->next_unit())
       {
         SELECT_LEX_NODE *save_slave= unit->slave;
+        if (unit == end_unit)
+          break;
         unit->include_down(table->select_lex);
         unit->slave= save_slave; // fix include_down initialisation
       }
Thread
bk commit into 5.0 tree (sergefp:1.1863) BUG#8490Sergey Petrunia22 Apr