Обсуждение: Oracle Analytic Functions for PostreSQL

Hi,
I have found Oracle analytic functions very useful. They are so convenient
to calculate running totals, moving averages, ranks, order data in
buckets... and so on. I have found in the archives a few threads that deal
with the replication of some of those functions on PostgreSQL but I don't
think I have the skills to write by myself such a package (I mean algorithms
can get pretty complicated). It seems that PostgreSQL does not offer the
equivalent (maybe because they do not belong to standard SQL?).  If I am
wrong thanks for letting me know where in the docs I can find details.
Otherwise, are you aware of an open-source project (maybe a corporation)
offering a set of equivalent functions ?
Many thanks
JCR