Could someone check my Postgresql queries? I wrote the explanation first and then the query.

# 1 list all sushi bars within borders of Cracow city
Code:
select name from planet_osm_point where amenity='restaurant' and name ilike '%sushi%' and ST_Within(way, (select multipolygon from krakow limit 1));
# 2 calculate the total length of aphalt roads in Cracow
Code:
select sum(st_length(way)) from planet_osm_roads where
...