Postgres find columns that don't have an index

gistfile1.txt

-- Looks at columns ending with '_id' (edit if needed in Where-clause)
select
  col.table_name,
  col.column_name,
  idx.indexdef
from information_schema.columns col
left join pg_indexes idx
  on col.table_name = idx.tablename 
  and idx.indexdef like '%' || col.column_name || '%'
where col.table_schema = 'public'
and col.column_name like '%_id'
and idx.indexdef is null
order by col.table_name, col.column_name