Extension:Comments/Comments block table

Schema
mysql> describe Comments_block; +--+-+--+-+-++ +--+-+--+-+-++ +--+-+--+-+-++
 * Field           | Type                | Null | Key | Default | Extra          |
 * cb_id           | int(11)             | NO   | PRI | NULL    | auto_increment |
 * cb_actor        | bigint(20) unsigned | NO   | MUL | NULL    |                |
 * cb_actor_blocked | bigint(20) unsigned | NO  |     | NULL    |                |
 * cb_date         | datetime            | YES  |     | NULL    |                |