Find all tables with a certain column name

    select n.nspname, 
           c.relname, 
           c.relnamespace, 
           c.relkind, 
           a.attname, 
           a.attrelid 
      from pg_attribute as a 
      join pg_catalog.pg_class as c 
        on a.attrelid = c.oid 
      join pg_catalog.pg_namespace as n 
        on c.relnamespace = n.oid 
     where a.attname = 'my_column' 
       and n.nspname = 'my_schema' 
       and c.relkind = 'r';