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From:Jorgen Loland Date:December 16 2010 2:12pm
Subject:bzr push into mysql-5.5-bugteam branch (jorgen.loland:3202 to 3203) Bug#58456
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 3203 Jorgen Loland	2010-12-16
      BUG#58456 - Assertion 0 in QUICK_INDEX_MERGE_SELECT::need_sorted_output 
                  in opt_range.h
      
      In this bug, there are two alternative access plans: 
       * Index merge range access
       * Const ref access
      
      best_access_path() decided that the ref access was preferrable, 
      but make_join_select() still decided to point 
      SQL_SELECT::quick to the index merge because the table had 
      type==JT_CONST which was not handled. 
      
      At the same time the table's ref.key still referred to the 
      index the ref access would use indicating that ref access 
      should be used. In this state, different parts of the 
      optimizer code have different perceptions of which access path
      is in use (ref or range).
      
      test_if_skip_sort_order() was called to check if the ref access
      needed ordering, but test_if_skip_sort_order() got confused and
      requested the index merge to return records in sorted order. 
      Index merge cannot do this, and fired an ASSERT.
      
      The fix is to take join_tab->type==JT_CONST into concideration
      when make_join_select() decides whether or not to use the 
      range access method.
     @ mysql-test/r/join_outer_innodb.result
        Add test for BUG#58456
     @ mysql-test/t/join_outer_innodb.test
        Add test for BUG#58456

    modified:
      mysql-test/r/join_outer_innodb.result
      mysql-test/t/join_outer_innodb.test
      sql/sql_select.cc
 3202 Jon Olav Hauglid	2010-12-16
      Bug #58730 Assertion failed: table->key_read == 0 in close_thread_table,
                 temptable views
      
      The TABLE::key_read field indicates if the optimizer has found that row
      retrieval only should access the index tree. The triggered assert
      inside close_thread_table() checks that this field has been reset when
      the table is about to be closed.
      
      During normal execution, these fields are reset right before tables are
      closed at the end of mysql_execute_command(). But in the case of errors,
      tables are closed earlier. The patch for Bug#52044 refactored the open
      tables code so that close_thread_tables() is called immediately if
      opening of tables fails. At this point in the execution, it could
      happend that all TABLE::key_read fields had not been properly reset,
      therefore triggering the assert.
      
      The problematic statement in this case was EXPLAIN where the query
      accessed two derived tables and where the first derived table was
      processed successfully while the second derived table was not.
      Since it was an EXPLAIN, TABLE::key_read fields were not reset after
      successful derived table processing since the state needs to be 
      accessible afterwards. When processing of the second derived table
      failed, it's corresponding SELECT_LEX_UNIT was cleaned, which caused
      it's TABLE::key_read fields to be reset. Since processing failed,
      the error path of open_and_lock_tables() was entered and
      close_thread_tables() was called. The assert was then triggered due
      to the TABLE::key_read fields set during processing of the first
      derived table.
      
      This patch fixes the problem by adding a new derived table processor,
      mysql_derived_cleanup() that is called after mysql_derived_filling().
      It causes cleanup of all SELECT_LEX_UNITs to be called, resetting
      all relevant TABLE::key_read fields.
      
      Test case added to derived.test.

    modified:
      mysql-test/r/derived.result
      mysql-test/t/derived.test
      sql/sql_base.cc
      sql/sql_derived.cc
      sql/sql_derived.h
      sql/sql_update.cc
=== modified file 'mysql-test/r/join_outer_innodb.result'
--- a/mysql-test/r/join_outer_innodb.result	2008-05-07 05:58:21 +0000
+++ b/mysql-test/r/join_outer_innodb.result	2010-12-16 11:25:02 +0000
@@ -17,3 +17,38 @@ id	select_type	table	type	possible_keys	
 1	SIMPLE	t2	index	NULL	fkey	5	NULL	5	Using index
 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.fkey	1	Using where
 DROP TABLE t1,t2;
+#
+# BUG#58456: Assertion 0 in QUICK_INDEX_MERGE_SELECT::need_sorted_output
+#            in opt_range.h
+#
+CREATE TABLE t1 (
+col_int INT,
+col_int_key INT,
+pk INT NOT NULL,
+PRIMARY KEY (pk),
+KEY col_int_key (col_int_key)
+) ENGINE=InnoDB;
+INSERT INTO t1 VALUES (NULL,1,1), (6,2,2), (5,3,3), (NULL,4,4);
+INSERT INTO t1 VALUES (1,NULL,6), (8,5,7), (NULL,8,8), (8,NULL,5);
+CREATE TABLE t2 (
+pk INT PRIMARY KEY
+) ENGINE=InnoDB;
+
+EXPLAIN SELECT t1.pk
+FROM t2 LEFT JOIN t1 ON t2.pk = t1.col_int
+WHERE t1.col_int_key BETWEEN 5 AND 6 
+AND t1.pk IS NULL OR t1.pk IN (5)
+ORDER BY pk;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	const	PRIMARY,col_int_key	PRIMARY	4	const	2	Using where
+1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.col_int	1	Using index
+
+SELECT t1.pk
+FROM t2 LEFT JOIN t1 ON t2.pk = t1.col_int
+WHERE t1.col_int_key BETWEEN 5 AND 6 
+AND t1.pk IS NULL OR t1.pk IN (5)
+ORDER BY pk;
+pk
+
+DROP TABLE t1,t2;
+# End BUG#58456

=== modified file 'mysql-test/t/join_outer_innodb.test'
--- a/mysql-test/t/join_outer_innodb.test	2006-05-22 11:57:32 +0000
+++ b/mysql-test/t/join_outer_innodb.test	2010-12-16 11:25:02 +0000
@@ -24,3 +24,40 @@ SELECT COUNT(*) FROM t2 LEFT JOIN t1 ON 
   WHERE t1.name LIKE 'A%' OR FALSE;
 
 DROP TABLE t1,t2;
+
+--echo #
+--echo # BUG#58456: Assertion 0 in QUICK_INDEX_MERGE_SELECT::need_sorted_output
+--echo #            in opt_range.h
+--echo #
+
+CREATE TABLE t1 (
+  col_int INT,
+  col_int_key INT,
+  pk INT NOT NULL,
+  PRIMARY KEY (pk),
+  KEY col_int_key (col_int_key)
+) ENGINE=InnoDB;
+
+INSERT INTO t1 VALUES (NULL,1,1), (6,2,2), (5,3,3), (NULL,4,4);
+INSERT INTO t1 VALUES (1,NULL,6), (8,5,7), (NULL,8,8), (8,NULL,5);
+
+CREATE TABLE t2 (
+  pk INT PRIMARY KEY
+) ENGINE=InnoDB;
+
+let $query=
+SELECT t1.pk
+FROM t2 LEFT JOIN t1 ON t2.pk = t1.col_int
+WHERE t1.col_int_key BETWEEN 5 AND 6 
+      AND t1.pk IS NULL OR t1.pk IN (5)
+ORDER BY pk;
+
+--echo
+--eval EXPLAIN $query
+--echo
+--eval $query
+--echo
+
+DROP TABLE t1,t2;
+
+--echo # End BUG#58456

=== modified file 'sql/sql_select.cc'
--- a/sql/sql_select.cc	2010-12-14 10:46:00 +0000
+++ b/sql/sql_select.cc	2010-12-16 11:25:02 +0000
@@ -6499,10 +6499,12 @@ make_join_select(JOIN *join,SQL_SELECT *
 	{
 	  /* Use quick key read if it's a constant and it's not used
 	     with key reading */
-	  if (tab->needed_reg.is_clear_all() && tab->type != JT_EQ_REF
-	      && tab->type != JT_FT && (tab->type != JT_REF ||
-               (uint) tab->ref.key == tab->quick->index))
-	  {
+          if (tab->needed_reg.is_clear_all() && tab->type != JT_EQ_REF &&
+              tab->type != JT_FT &&
+              ((tab->type != JT_CONST && tab->type != JT_REF) ||
+               (uint)tab->ref.key == tab->quick->index))
+          {
+            DBUG_ASSERT(tab->quick->index != MAX_KEY);
 	    sel->quick=tab->quick;		// Use value from get_quick_...
 	    sel->quick_keys.clear_all();
 	    sel->needed_reg.clear_all();
@@ -13857,7 +13859,7 @@ check_reverse_order:                  
   SYNOPSIS
    create_sort_index()
      thd		Thread handler
-     tab		Table to sort (in join structure)
+     join		Join with table to sort
      order		How table should be sorted
      filesort_limit	Max number of rows that needs to be sorted
      select_limit	Max number of rows in final output
@@ -13867,8 +13869,8 @@ check_reverse_order:                  
 
 
   IMPLEMENTATION
-   - If there is an index that can be used, 'tab' is modified to use
-     this index.
+   - If there is an index that can be used, the first non-const join_tab in
+     'join' is modified to use this index.
    - If no index, create with filesort() an index file that can be used to
      retrieve rows in order (should be done with 'read_record').
      The sorted data is stored in tab->table and will be freed when calling

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bzr push into mysql-5.5-bugteam branch (jorgen.loland:3202 to 3203) Bug#58456Jorgen Loland16 Dec