r-m-n

class Cidr(postgresql.CIDR):
    '''
    Делаем свой тип колонки для того, чтобы была возможность использовать
    операторы >> и <<
    '''
    class comparator_factory(postgresql.CIDR.Comparator):
        def __lshift__(self, other):
            return self.op("<<")(other)
        def __rshift__(self, other):
            return self.op(">>")(other)

r-m-n

SELECT 
        n.nspname               AS "schema",
        c.relname               AS "index"
FROM 
        pg_catalog.pg_class AS c 
        LEFT JOIN pg_catalog.pg_namespace AS n ON n.oid = c.relnamespace
WHERE
        c.relkind = 'i'
        AND 
        n.nspname NOT IN ('pg_catalog', 'pg_toast')