id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2262	NULL
2	DERIVED	album	index	PRIMARY	PRIMARY	4	NULL	2262	Using where
2	DERIVED	album_tag_assn	eq_ref	PRIMARY	PRIMARY	8	bsr.album.album_id,const	1	Using index