id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	cat	NULL	index	PRIMARY,name	name	194	NULL	1	100	Using index
1	PRIMARY	cat	NULL	eq_ref	PRIMARY,name	name	194	mysql.cat.name	1	100	Using index
1	PRIMARY	sch	NULL	eq_ref	PRIMARY,catalog_id	catalog_id	202	mysql.cat.id,const	1	100	Using index
1	PRIMARY	sch	NULL	eq_ref	PRIMARY,catalog_id	catalog_id	202	mysql.cat.id,const	1	100	Using index
1	PRIMARY	tbl	NULL	eq_ref	schema_id	schema_id	202	mysql.sch.id,const	1	100	Rematerialize (<derived4>)
1	PRIMARY	fk	NULL	ref	schema_id,table_id	schema_id	8	mysql.sch.id	78	100	NULL
1	PRIMARY	tbl	NULL	eq_ref	PRIMARY	PRIMARY	8	mysql.fk.table_id	1	10	Using where
1	PRIMARY	<derived4>	NULL	ref	<auto_key0>	<auto_key0>	194	func	2	100	Using where
1	PRIMARY	col	NULL	eq_ref	PRIMARY	PRIMARY	8	constraints.column_id	1	100	Using where
4	DEPENDENT DERIVED	idx	NULL	ref	PRIMARY,table_id	table_id	8	mysql.tbl.id	2	40	Using where
4	DEPENDENT DERIVED	icu	NULL	ref	index_id,index_id_2	index_id	8	mysql.idx.id	5	100	NULL
5	DEPENDENT UNION	fk	NULL	ref	PRIMARY,table_id	table_id	8	mysql.tbl.id	2	100	NULL
5	DEPENDENT UNION	fkcu	NULL	ref	PRIMARY,foreign_key_id	foreign_key_id	8	mysql.fk.id	1	100	Using index