Merge

mysql-test/r/join_cache.result

@@ -5637,4 +5637,23 @@ c
 set join_buffer_size=default;
 set optimizer_switch=@tmp_optimizer_switch;
 DROP table t1,t2,t3;
+set join_buffer_size= default;
+set @@optimizer_switch=@save_optimizer_switch;
+#
+# MDEV-5293: outer join, join buffering, and order by - invalid query plan
+#
+create table t0 (a int primary key) engine=myisam;
+insert into t0 values (1);
+create table t1(a int) engine=myisam;
+insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+alter table t1 add b int;
+create table t2 like t1;
+insert into t2 select * from t1;
+#The following must use "Using temporary; Using filesort" and not just "Using filesort":
+explain select * from t0,t1 left join t2 on t1.b=t2.b order by t0.a, t1.a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t0	system	NULL	NULL	NULL	NULL	1	Using temporary; Using filesort
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer (flat, BNL join)
+drop table t0,t1,t2;
 set @@optimizer_switch=@save_optimizer_switch;

mysql-test/r/subselect_sj.result

@@ -2920,4 +2920,37 @@ COUNT(*)
 DROP TABLE t1, t2, t3;
 set join_buffer_size = @tmp_join_buffer_size;
 set max_heap_table_size = @tmp_max_heap_table_size;
+#
+# MDEV-5161: Wrong result (missing rows) with semijoin, LEFT JOIN, ORDER BY, constant table
+#
+select @@optimizer_switch;
+@@optimizer_switch
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=off,table_elimination=on,extended_keys=off
+select @@join_cache_level;
+@@join_cache_level
+1
+CREATE TABLE t1 (pk INT PRIMARY KEY, c1 VARCHAR(1)) ENGINE=MyISAM;
+INSERT INTO t1 VALUES (1,'v'),(2,'v'),(3,'c'),(4,NULL),(5,'x');
+CREATE TABLE t2 (c2 VARCHAR(1)) ENGINE=MyISAM;
+INSERT INTO t2 VALUES ('x');
+CREATE TABLE t3 (c3 VARCHAR(1)) ENGINE=MyISAM;
+INSERT INTO t3 VALUES ('x'),('d');
+SELECT * FROM t1, t2 WHERE pk IN ( SELECT pk FROM t1 LEFT JOIN t3 ON (c1 = c3 ) ) ORDER BY c2, c1;
+pk	c1	c2
+4	NULL	x
+3	c	x
+1	v	x
+2	v	x
+5	x	x
+# This should show that "t1 left join t3" is still in the semi-join nest:
+EXPLAIN EXTENDED
+SELECT * FROM t1, t2 WHERE pk IN ( SELECT pk FROM t1 LEFT JOIN t3 ON (c1 = c3 ) ) ORDER BY c2, c1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	100.00	Using temporary; Using filesort
+1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	5	100.00	Start temporary
+1	PRIMARY	t1	eq_ref	PRIMARY	PRIMARY	4	test.t1.pk	1	100.00	
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; End temporary
+Warnings:
+Note	1003	select `test`.`t1`.`pk` AS `pk`,`test`.`t1`.`c1` AS `c1`,'x' AS `c2` from `test`.`t1` semi join (`test`.`t1` left join `test`.`t3` on((`test`.`t1`.`c1` = `test`.`t3`.`c3`))) where (`test`.`t1`.`pk` = `test`.`t1`.`pk`) order by 'x',`test`.`t1`.`c1`
+DROP TABLE t1,t2,t3;
 set optimizer_switch=@subselect_sj_tmp;

mysql-test/r/subselect_sj_jcl6.result

@@ -2934,6 +2934,39 @@ COUNT(*)
 DROP TABLE t1, t2, t3;
 set join_buffer_size = @tmp_join_buffer_size;
 set max_heap_table_size = @tmp_max_heap_table_size;
+#
+# MDEV-5161: Wrong result (missing rows) with semijoin, LEFT JOIN, ORDER BY, constant table
+#
+select @@optimizer_switch;
+@@optimizer_switch
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=off,mrr_sort_keys=on,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=off,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=off
+select @@join_cache_level;
+@@join_cache_level
+6
+CREATE TABLE t1 (pk INT PRIMARY KEY, c1 VARCHAR(1)) ENGINE=MyISAM;
+INSERT INTO t1 VALUES (1,'v'),(2,'v'),(3,'c'),(4,NULL),(5,'x');
+CREATE TABLE t2 (c2 VARCHAR(1)) ENGINE=MyISAM;
+INSERT INTO t2 VALUES ('x');
+CREATE TABLE t3 (c3 VARCHAR(1)) ENGINE=MyISAM;
+INSERT INTO t3 VALUES ('x'),('d');
+SELECT * FROM t1, t2 WHERE pk IN ( SELECT pk FROM t1 LEFT JOIN t3 ON (c1 = c3 ) ) ORDER BY c2, c1;
+pk	c1	c2
+4	NULL	x
+3	c	x
+1	v	x
+2	v	x
+5	x	x
+# This should show that "t1 left join t3" is still in the semi-join nest:
+EXPLAIN EXTENDED
+SELECT * FROM t1, t2 WHERE pk IN ( SELECT pk FROM t1 LEFT JOIN t3 ON (c1 = c3 ) ) ORDER BY c2, c1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	PRIMARY	t2	system	NULL	NULL	NULL	NULL	1	100.00	Using temporary; Using filesort
+1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	5	100.00	Start temporary
+1	PRIMARY	t1	eq_ref	PRIMARY	PRIMARY	4	test.t1.pk	1	100.00	Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where; End temporary; Using join buffer (incremental, BNL join)
+Warnings:
+Note	1003	select `test`.`t1`.`pk` AS `pk`,`test`.`t1`.`c1` AS `c1`,'x' AS `c2` from `test`.`t1` semi join (`test`.`t1` left join `test`.`t3` on((`test`.`t1`.`c1` = `test`.`t3`.`c3`))) where (`test`.`t1`.`pk` = `test`.`t1`.`pk`) order by 'x',`test`.`t1`.`c1`
+DROP TABLE t1,t2,t3;
 set optimizer_switch=@subselect_sj_tmp;
 #
 # BUG#49129: Wrong result with IN-subquery with join_cache_level=6 and firstmatch=off

mysql-test/t/join_cache.test

@@ -3635,6 +3635,26 @@ set join_buffer_size=default;
 set optimizer_switch=@tmp_optimizer_switch;
 
 DROP table t1,t2,t3;
+set join_buffer_size= default;
+set @@optimizer_switch=@save_optimizer_switch;
+
+
+--echo #
+--echo # MDEV-5293: outer join, join buffering, and order by - invalid query plan
+--echo #
+create table t0 (a int primary key) engine=myisam;
+insert into t0 values (1);
+
+create table t1(a int) engine=myisam;
+insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+alter table t1 add b int;
+
+create table t2 like t1;
+insert into t2 select * from t1;
+--echo #The following must use "Using temporary; Using filesort" and not just "Using filesort":
+explain select * from t0,t1 left join t2 on t1.b=t2.b order by t0.a, t1.a;
+
+drop table t0,t1,t2;
 
 # this must be the last command in the file
 set @@optimizer_switch=@save_optimizer_switch;

mysql-test/t/subselect_sj.test

@@ -2622,5 +2622,26 @@ DROP TABLE t1, t2, t3;
 set join_buffer_size = @tmp_join_buffer_size;
 set max_heap_table_size = @tmp_max_heap_table_size;
 
+--echo #
+--echo # MDEV-5161: Wrong result (missing rows) with semijoin, LEFT JOIN, ORDER BY, constant table
+--echo #
+select @@optimizer_switch;
+select @@join_cache_level;
+CREATE TABLE t1 (pk INT PRIMARY KEY, c1 VARCHAR(1)) ENGINE=MyISAM;
+INSERT INTO t1 VALUES (1,'v'),(2,'v'),(3,'c'),(4,NULL),(5,'x');
+
+CREATE TABLE t2 (c2 VARCHAR(1)) ENGINE=MyISAM;
+INSERT INTO t2 VALUES ('x');
+
+CREATE TABLE t3 (c3 VARCHAR(1)) ENGINE=MyISAM;
+INSERT INTO t3 VALUES ('x'),('d');
+
+SELECT * FROM t1, t2 WHERE pk IN ( SELECT pk FROM t1 LEFT JOIN t3 ON (c1 = c3 ) ) ORDER BY c2, c1;
+
+--echo # This should show that "t1 left join t3" is still in the semi-join nest:
+EXPLAIN EXTENDED
+SELECT * FROM t1, t2 WHERE pk IN ( SELECT pk FROM t1 LEFT JOIN t3 ON (c1 = c3 ) ) ORDER BY c2, c1;
+
+DROP TABLE t1,t2,t3;
 # The following command must be the last one the file 
 set optimizer_switch=@subselect_sj_tmp;

sql/opt_subselect.cc

@@ -1921,11 +1921,25 @@ int pull_out_semijoin_tables(JOIN *join)
       }
     }
     
-    
     table_map pulled_tables= 0;
+    table_map dep_tables= 0;
     if (have_join_nest_children)
       goto skip;
 
+    /*
+      Calculate set of tables within this semi-join nest that have
+      other dependent tables
+    */
+    child_li.rewind();
+    while ((tbl= child_li++))
+    {
+      TABLE *const table= tbl->table;
+      if (table &&
+         (table->reginfo.join_tab->dependent &
+          sj_nest->nested_join->used_tables))
+        dep_tables|= table->reginfo.join_tab->dependent;
+    }
+
     /* Action #1: Mark the constant tables to be pulled out */
     child_li.rewind();
     while ((tbl= child_li++))
@@ -1976,7 +1990,8 @@ int pull_out_semijoin_tables(JOIN *join)
       child_li.rewind();
       while ((tbl= child_li++))
       {
-        if (tbl->table && !(pulled_tables & tbl->table->map))
+        if (tbl->table && !(pulled_tables & tbl->table->map) &&
+            !(dep_tables & tbl->table->map))
         {
           if (find_eq_ref_candidate(tbl->table, 
                                     sj_nest->nested_join->used_tables & 

sql/sql_select.cc

@@ -241,7 +241,8 @@ static ORDER *create_distinct_group(THD *thd, Item **ref_pointer_array,
                                     List<Item> &all_fields,
 				    bool *all_order_by_fields_used);
 static bool test_if_subpart(ORDER *a,ORDER *b);
-static TABLE *get_sort_by_table(ORDER *a,ORDER *b,List<TABLE_LIST> &tables);
+static TABLE *get_sort_by_table(ORDER *a,ORDER *b,List<TABLE_LIST> &tables, 
+                                table_map const_tables);
 static void calc_group_buffer(JOIN *join,ORDER *group);
 static bool make_group_fields(JOIN *main_join, JOIN *curr_join);
 static bool alloc_group_fields(JOIN *join,ORDER *group);
@@ -1211,7 +1212,8 @@ JOIN::optimize()
     goto setup_subq_exit;
   }
   error= -1;					// Error is sent to client
-  sort_by_table= get_sort_by_table(order, group_list, select_lex->leaf_tables);
+  /* get_sort_by_table() call used to be here: */
+  MEM_UNDEFINED(&sort_by_table, sizeof(sort_by_table));
 
   /* Calculate how to do the join */
   thd_proc_info(thd, "statistics");
@@ -3583,6 +3585,9 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
     }
   } while (join->const_table_map & found_ref && ref_changed);
  
+  join->sort_by_table= get_sort_by_table(join->order, join->group_list,
+                                         join->select_lex->leaf_tables,
+                                         join->const_table_map);
   /* 
     Update info on indexes that can be used for search lookups as
     reading const tables may has added new sargable predicates. 
@@ -10284,6 +10289,22 @@ make_join_readinfo(JOIN *join, ulonglong options, uint no_jbuf_after)
                               join->group_list ?
 			       join->join_tab+join->const_tables :
                                join->get_sort_by_join_tab();
+      /*
+        It could be that sort_by_tab==NULL, and the plan is to use filesort()
+        on the first table.
+      */
+      if (join->order)
+      {
+        join->simple_order= 0;
+        join->need_tmp= 1;
+      }
+
+      if (join->group && !join->group_optimized_away)
+      {
+        join->need_tmp= 1;
+        join->simple_group= 0;
+      }
+      
       if (sort_by_tab)
       {
         join->need_tmp= 1;
@@ -20714,7 +20735,8 @@ test_if_subpart(ORDER *a,ORDER *b)
 */
 
 static TABLE *
-get_sort_by_table(ORDER *a,ORDER *b, List<TABLE_LIST> &tables)
+get_sort_by_table(ORDER *a,ORDER *b, List<TABLE_LIST> &tables, 
+                  table_map const_tables)
 {
   TABLE_LIST *table;
   List_iterator<TABLE_LIST> ti(tables);
@@ -20728,6 +20750,23 @@ get_sort_by_table(ORDER *a,ORDER *b, List<TABLE_LIST> &tables)
 
   for (; a && b; a=a->next,b=b->next)
   {
+    /* Skip elements of a that are constant */
+    while (!((*a->item)->used_tables() & ~const_tables))
+    {
+      if (!(a= a->next))
+        break;
+    }
+
+    /* Skip elements of b that are constant */
+    while (!((*b->item)->used_tables() & ~const_tables))
+    {
+      if (!(b= b->next))
+        break;
+    }
+
+    if (!a || !b)
+      break;
+
     if (!(*a->item)->eq(*b->item,1))
       DBUG_RETURN(0);
     map|=a->item[0]->used_tables();