mysql> SELECT COUNT(id), COUNT(DISTINCT id)
    -> FROM podcat_biz;
+-----------+--------------------+
| COUNT(id) | COUNT(DISTINCT id) |
+-----------+--------------------+
|       691 |                691 |
+-----------+--------------------+
1 row in set (0.18 sec)

mysql> SELECT COUNT(podcat_id), COUNT(DISTINCT podcat_id) FROM post_biz_ua;
+------------------+---------------------------+
| COUNT(podcat_id) | COUNT(DISTINCT podcat_id) |
+------------------+---------------------------+
|           431482 |                       646 |
+------------------+---------------------------+
1 row in set (0.41 sec)