Fixed bug mdev-4406.

This bug in the code of get_column_range_cardinality() could lead to
wrong estimates of number of records in ranges for non-nullable columns.  

1 files changed, 31 insertions, 0 deletions

diff --git a/mysql-test/t/selectivity.test b/mysql-test/t/selectivity.test
index 8bde4718fdd..47f62365816 100644
--- a/mysql-test/t/selectivity.test
+++ b/mysql-test/t/selectivity.test
@@ -676,5 +676,36 @@ DROP TABLE t1,t2;
 
 set use_stat_tables=@save_use_stat_tables;
 
+--echo #
+--echo # Bug mdev-4406: range condition for non-nullable column   
+--echo #                when optimizer_use_condition_selectivity=3
+--echo #
+
+create table t1 (a int not null);
+insert into t1 values
+  (7), (6), (4), (9), (1), (5), (2), (1), (3), (8);
+
+set use_stat_tables='preferably';
+
+analyze table t1;
+flush table t1;
+
+set optimizer_use_condition_selectivity=3;
+
+select count(*) from t1 where a between 5 and 7;
+explain extended select * from t1 where a between 5 and 7;
+
+alter table t1 change column a a int;
+analyze table t1;
+flush table t1;
+
+explain extended select * from t1 where a between 5 and 7;
+
+set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
+
+drop table t1;
+
+set use_stat_tables=@save_use_stat_tables;
+
 
 set use_stat_tables=@save_use_stat_tables;