Gerhard Heift <ml-postgresql-20081012-3518@xxxxxxxxx> writes: > The function is called for every row in the table if it is stable or > volatile and only once if it is immutable? Yes, possibly. > I thought it had to be called only once, if it is stable. No. Stable means that it is *okay* to call it only once per query, not that that is *guaranteed* to happen. (What it really does is give the planner license to use an indexscan on a condition involving the function --- an indexscan's comparison value is evaluated just once, so it would give the wrong answers for a non-stable function.) regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
