mysql>explain select * from vw_rgroups where cluster='uxorionc010';
+----+-------------+------------+--------+---------------+---------+---------+-------------------------------+------+---------------------------------+
| id | select_type | table      | type   | possible_keys | key     | key_len | ref                           | rows | Extra                           |
+----+-------------+------------+--------+---------------+---------+---------+-------------------------------+------+---------------------------------+
|  1 | PRIMARY     | <derived2> | ALL    | NULL          | NULL    | NULL    | NULL                          |  525 | Using where                     | 
|  2 | DERIVED     | cl         | ALL    | PRIMARY       | NULL    | NULL    | NULL                          |   26 | Using temporary; Using filesort | 
|  2 | DERIVED     | jt1        | ref    | PRIMARY       | PRIMARY | 4       | ucc.cl.id                     |    1 | Using index                     | 
|  2 | DERIVED     | srv        | eq_ref | PRIMARY       | PRIMARY | 4       | ucc.jt1.id_server             |    1 |                                 | 
|  2 | DERIVED     | rg         | ref    | PRIMARY       | PRIMARY | 4       | ucc.jt1.id_cluster            |    5 | Using where                     | 
|  2 | DERIVED     | cnode      | eq_ref | PRIMARY       | PRIMARY | 4       | ucc.rg.id_current             |    1 |                                 | 
|  2 | DERIVED     | jt2        | ref    | PRIMARY       | PRIMARY | 261     | ucc.rg.id_cluster,ucc.rg.name |    4 | Using index                     | 
|  2 | DERIVED     | vs         | eq_ref | PRIMARY       | PRIMARY | 4       | ucc.jt2.id_vserver            |    1 |                                 | 
+----+-------------+------------+--------+---------------+---------+---------+-------------------------------+------+---------------------------------+