Hello,
I was able to duplicate the following sequence in both 4.0.14-max and 4.0.16. It happens in all my tables. I do not understand why the cardinality for the date_created field does not = 223284. mysql> select count(distinct date_created) from POSTING ; +------------------------------+ | count(distinct date_created) | +------------------------------+ | 223284 | +------------------------------+ 1 row in set (2.48 sec) mysql> analyze table POSTING ; +---------------+---------+----------+----------+ | Table | Op | Msg_type | Msg_text | +---------------+---------+----------+----------+ | TRIBE.POSTING | analyze | status | OK | +---------------+---------+----------+----------+ 1 row in set (16.74 sec) mysql> show index from POSTING ; +---------+------------+----------------------------+--------------+-------- --------+-----------+-------------+----------+--------+------+------------+- --------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | +---------+------------+----------------------------+--------------+-------- --------+-----------+-------------+----------+--------+------+------------+- --------+ | POSTING | 0 | PRIMARY | 1 | ID | A | 228383 | NULL | NULL | | BTREE | | | POSTING | 1 | posting_id_idx | 1 | ID | A | 228383 | NULL | NULL | | BTREE | | | POSTING | 1 | posting_owner_id_idx | 1 | OWNER_ID | A | 6010 | NULL | NULL | | BTREE | | | POSTING | 1 | posting_parent_id_idx | 1 | PARENT_ID | A | 114191 | NULL | NULL | YES | BTREE | | | POSTING | 1 | posting_thread_id_idx | 1 | THREAD_ID | A | 45676 | NULL | NULL | YES | BTREE | | | POSTING | 1 | posting_from_person_id_idx | 1 | FROM_PERSON_ID | A | 9929 | NULL | NULL | | BTREE | | | POSTING | 1 | posting_date_created | 1 | DATE_CREATED | A | 228383 | NULL | NULL | YES | BTREE | | | POSTING | 1 | posting_is_deleted_idx | 1 | IS_DELETED | A | 1 | NULL | NULL | | BTREE | | +---------+------------+----------------------------+--------------+-------- --------+-----------+-------------+----------+--------+------+------------+- --------+ 8 rows in set (0.00 sec) mysql> select count(distinct date_created) from POSTING ; +------------------------------+ | count(distinct date_created) | +------------------------------+ | 223284 | Thanks, Trevor