UNION or SELF JOIN?

I have a table to hold parent and child posts together. +------+----------------+--------------+-------------+------------+ | p_id | parent_post_id | child_status | post_status | post_title | +------+----------------+--------------+-------------+------------+ | 1 | 0 | 1 | publish | New 1 | | 2 | 1 | 0 | publish | ab 1 | | 3 | 1 | 0 | publish | ab2 | | 4 | 0 | 0 | publish | new2 | | 5 | 4 | 0 | publish | ab3 | +------+----------------+--------------+-------------+------------+ I want to show all parents from this table along with the child posts if the child_status of the parent is set to true. Currently I use a self join to accomplish the same SELECT p1.* FROM wp_bw_post p1 LEFT OUTER JOIN wp_bw_post p2 ON p1.parent_post_id=p2.p_id WHERE (p1.parent_post_id=0 OR p2.child_status=1) AND p1.post_status="publish"; which gives me the expected results. +------+----------------+--------------+-------------+------------+ | p_id | parent_post_id | child_status | post_status | post_title | +------+----------------+--------------+-------------+------------+ | 1 | 0 | 1 | publish | New 1 | | 2 | 1 | 0 | publish | ab 1 | | 3 | 1 | 0 | publish | ab2 | | 4 | 0 | 0 | publish | new2 | +------+----------------+--------------+-------------+------------+ 4 rows in set (0.00 sec). Performance is my great concern as this data is presented using infinite scroll.The table is expected to have millions of records and I need to present it as a single queue using some where and orderby conditions. Is this the efficient way to do this, or should I store the parent and child posts in a different table and fetch all using UNION?