id  	 select_type  	 table  	 type  	 possible_keys  	 key  	 key_len  	 ref  	 rows  	 Extra
1 	SIMPLE 	pr 	system 	text,artistid 	NULL 	NULL 	NULL 	1 	 
1 	SIMPLE 	a 	ALL 	PRIMARY,crammed 	NULL 	NULL 	NULL 	15420 	Using where