PostgreSQL find locks including the table name

Question

I'm trying to take a look at locks that are happening on specific tables in my PostgreSQL database.

I see there's a table called pg_locks

select * from pg_locks;

Which seems to give me a bunch of columns but is it possible to find the relation because I see one of the columns is the relation oid.

What table must I link that to to get the relation name?

Answer 1

This is Remy's query, adjusted for Postgres 10:

select nspname, relname, l.* 
from pg_locks l 
    join pg_class c on (relation = c.oid) 
    join pg_namespace nsp on (c.relnamespace = nsp.oid)
where pid in (select pid 
              from pg_stat_activity
              where datname = current_database() 
                and query != current_query());

Answer 2

If you just want the contents of pg_locks but with a human-friendly relation name,

select relation::regclass, * from pg_locks;