Scara Maccai <m_li...@yahoo.it> writes: > It would be very easy if the input to the custom aggregate function was > ordered (because I would keep 4 internal counters), but I guess there's > no way of "forcing" the ordering of the input to the function, right?
You can with a subquery. Something like SELECT agg(foo) from (SELECT foo ORDER BY bar) However that will produce one record per grouping. From what I read of your description you want to produce one record per input record. There isn't any efficient way to do that in current Postgres releases -- you would have to have a subquery which executed for every record and retrieved the set of data to aggregate. 8.4 Will have OLAP Window functions which can implement things like moving averages. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com Get trained by Bruce Momjian - ask me about EnterpriseDB's PostgreSQL training! -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
