Fixed bug mdev-4349.

Range analysis of the condition for a non-indexed column may
return an impossible range. This must be taken into account.

mysql-test/r/selectivity.result

@@ -675,4 +675,44 @@ DROP VIEW v1;
 DROP TABLE t1,t2;
 set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
 set use_stat_tables=@tmp_use_stat_tables;
+#
+# Bug mdev-4349: impossible range for non-indexed column 
+#
+set optimizer_use_condition_selectivity=3;
+create table t1 (a int);
+insert into t1 values
+(3), (7), (2), (5), (7), (1), (2), (2);
+set optimizer_use_condition_selectivity=1;
+explain extended
+select * from t1 where a < 1 and a > 7;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	8	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where ((`test`.`t1`.`a` < 1) and (`test`.`t1`.`a` > 7))
+select * from t1 where a < 1 and a > 7;
+a
+set optimizer_use_condition_selectivity=3;
+explain extended
+select * from t1 where a < 1 and a > 7;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where 0
+select * from t1 where a < 1 and a > 7;
+a
+drop table t1;
+create table t1 (a int);
+insert into t1 values (1);
+create table t2 (b int);
+insert into t2 values (2),(3);
+explain extended 
+select * from t1 where a in ( select b from t2 ) AND ( a > 3 );
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+Warnings:
+Note	1003	select 1 AS `a` from (`test`.`t2`) where 0
+select * from t1 where a in ( select b from t2 ) AND ( a > 3 );
+a
+drop table t1,t2;
+set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
 set use_stat_tables=@save_use_stat_tables;

mysql-test/r/selectivity_innodb.result

@@ -681,6 +681,47 @@ DROP VIEW v1;
 DROP TABLE t1,t2;
 set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
 set use_stat_tables=@tmp_use_stat_tables;
+#
+# Bug mdev-4349: impossible range for non-indexed column 
+#
+set optimizer_use_condition_selectivity=3;
+create table t1 (a int);
+insert into t1 values
+(3), (7), (2), (5), (7), (1), (2), (2);
+set optimizer_use_condition_selectivity=1;
+explain extended
+select * from t1 where a < 1 and a > 7;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	8	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where ((`test`.`t1`.`a` < 1) and (`test`.`t1`.`a` > 7))
+select * from t1 where a < 1 and a > 7;
+a
+set optimizer_use_condition_selectivity=3;
+explain extended
+select * from t1 where a < 1 and a > 7;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where 0
+select * from t1 where a < 1 and a > 7;
+a
+drop table t1;
+create table t1 (a int);
+insert into t1 values (1);
+create table t2 (b int);
+insert into t2 values (2),(3);
+explain extended 
+select * from t1 where a in ( select b from t2 ) AND ( a > 3 );
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	1	0.00	Using where
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	0	Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`b` = `test`.`t1`.`a`) and (`test`.`t1`.`a` > 3))
+select * from t1 where a in ( select b from t2 ) AND ( a > 3 );
+a
+drop table t1,t2;
+set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
 set use_stat_tables=@save_use_stat_tables;
 set optimizer_switch=@save_optimizer_switch_for_selectivity_test;
 SET SESSION STORAGE_ENGINE=DEFAULT;

mysql-test/t/selectivity.test

@@ -267,5 +267,40 @@ DROP TABLE t1,t2;
 set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
 set use_stat_tables=@tmp_use_stat_tables; 
 
+--echo #
+--echo # Bug mdev-4349: impossible range for non-indexed column 
+--echo #
+
+set optimizer_use_condition_selectivity=3;
+
+create table t1 (a int);
+insert into t1 values
+  (3), (7), (2), (5), (7), (1), (2), (2);
+
+set optimizer_use_condition_selectivity=1;
+explain extended
+select * from t1 where a < 1 and a > 7;
+select * from t1 where a < 1 and a > 7;
+
+set optimizer_use_condition_selectivity=3;
+explain extended
+select * from t1 where a < 1 and a > 7;
+select * from t1 where a < 1 and a > 7;
+
+drop table t1;
+
+create table t1 (a int);
+insert into t1 values (1);
+
+create table t2 (b int);
+insert into t2 values (2),(3);
+
+explain extended 
+select * from t1 where a in ( select b from t2 ) AND ( a > 3 );
+select * from t1 where a in ( select b from t2 ) AND ( a > 3 );
+
+drop table t1,t2;
+
+set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
 
 set use_stat_tables=@save_use_stat_tables;

sql/opt_range.cc

@@ -3325,7 +3325,8 @@ bool calculate_cond_selectivity_for_table(THD *thd, TABLE *table, Item *cond)
 
   table->cond_selectivity= 1.0;
   
-  if (!bitmap_is_clear_all(used_fields))
+  if (thd->variables.optimizer_use_condition_selectivity > 2 &&
+      !bitmap_is_clear_all(used_fields))
   {
     PARAM param;
     MEM_ROOT alloc;
@@ -3362,9 +3363,25 @@ bool calculate_cond_selectivity_for_table(THD *thd, TABLE *table, Item *cond)
       double rows;
       if (*key)
       {
+#if 0
         rows= records_in_column_ranges(&param, idx, *key);
         if (rows != HA_POS_ERROR)
           (*key)->field->cond_selectivity= rows/table_records; 
+#else
+        table->reginfo.impossible_range= 0;
+        if ((*key)->type == SEL_ARG::IMPOSSIBLE)
+	{
+          rows= 0;
+          table->reginfo.impossible_range= 1;
+          goto free_alloc;
+        }          
+        else
+        {
+          rows= records_in_column_ranges(&param, idx, *key);
+          if (rows != HA_POS_ERROR)
+            (*key)->field->cond_selectivity= rows/table_records;
+        } 
+#endif
       }
     }
 

sql/sql_select.cc

@@ -3794,6 +3794,8 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
       all select distinct fields participate in one index.
     */
     add_group_and_distinct_keys(join, s);
+
+    table->cond_selectivity= 1.0;
     
     /*
       Perform range analysis if there are keys it could use (1). 
@@ -3802,7 +3804,8 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
       Don't do range analysis for materialized subqueries (4).
       Don't do range analysis for materialized derived tables (5)
     */
-    if (!s->const_keys.is_clear_all() &&                            // (1)
+    if ((!s->const_keys.is_clear_all() ||
+	 !bitmap_is_clear_all(&s->table->cond_set)) &&              // (1)
         (!s->table->pos_in_table_list->embedding ||                 // (2)
          (s->table->pos_in_table_list->embedding &&                 // (3)
           s->table->pos_in_table_list->embedding->sj_on_expr)) &&   // (3)
@@ -3810,20 +3813,37 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
         !(s->table->pos_in_table_list->derived &&                   // (5)
           s->table->pos_in_table_list->is_materialized_derived()))  // (5)
     {
-      ha_rows records;
-      SQL_SELECT *select;
-      select= make_select(s->table, found_const_table_map,
-			  found_const_table_map,
-			  *s->on_expr_ref ? *s->on_expr_ref : conds,
-			  1, &error);
-      if (!select)
-        goto error;
-      records= get_quick_record_count(join->thd, select, s->table,
-				      &s->const_keys, join->row_limit);
-      s->quick=select->quick;
-      s->needed_reg=select->needed_reg;
-      select->quick=0;
-      if (records == 0 && s->table->reginfo.impossible_range)
+      bool impossible_range= FALSE;
+      ha_rows records= HA_POS_ERROR;
+      SQL_SELECT *select= 0;
+      if (!s->const_keys.is_clear_all())
+      {
+        select= make_select(s->table, found_const_table_map,
+			    found_const_table_map,
+			    *s->on_expr_ref ? *s->on_expr_ref : conds,
+			    1, &error);
+        if (!select)
+          goto error;
+        records= get_quick_record_count(join->thd, select, s->table,
+				        &s->const_keys, join->row_limit);
+        s->quick=select->quick;
+        s->needed_reg=select->needed_reg;
+        select->quick=0;
+        impossible_range= records == 0 && s->table->reginfo.impossible_range;
+      }
+      if (!impossible_range)
+      {
+        if (join->thd->variables.optimizer_use_condition_selectivity > 1)
+          calculate_cond_selectivity_for_table(join->thd, s->table, 
+                                               *s->on_expr_ref ?
+                                               *s->on_expr_ref : conds);
+        if (s->table->reginfo.impossible_range)
+	{
+          impossible_range= TRUE;
+          records= 0;
+        }
+      }
+      if (impossible_range)
       {
 	/*
 	  Impossible WHERE or ON expression
@@ -3848,13 +3868,10 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
 	s->found_records=records;
 	s->read_time= s->quick ? s->quick->read_time : 0.0;
       }
-      delete select;
+      if (select)
+        delete select;
     }
 
-    if (join->thd->variables.optimizer_use_condition_selectivity > 1)
-      calculate_cond_selectivity_for_table(join->thd, s->table, 
-                                           *s->on_expr_ref ?
-                                           *s->on_expr_ref : conds);
   }
 
   if (pull_out_semijoin_tables(join))