1	PRIMARY	<derived2>	ALL					691552	Using where
2	DERIVED	b	index	PRIMARY,city_id	PRIMARY	8		172886	Using where
2	DERIVED	bt	ref	alias_id	alias_id	4	outdoor.b.type_id	1	Using index condition
2	DERIVED	build_property	ref	name,build_id	build_id	8	outdoor.b.id	8	Using index condition; Using where