Quick question, just curious - is there a way to access the members of a `pg_node_tree` value within a Postgres query? By pg_node_tree I mean for example, the `ev_qual` field in the `pg_rewrite` table. By "access the members" I mean in the same way that you can access the members of a json or jsonp value (using -> or ->>). Is there anything analogous for pg_node_tree?
