I use postgresql-9.1 with ubuntu 12.04. I need to select records inside a range of time: my table time_limits has two timestamp fields and one property integer. Indeed there are other info columns ...
While looking at several examples of pl/python and pl/pgsql, I have seen many - but not all - using volatile cost. ie: CREATE OR REPLACE FUNCTION my_function() RETURNS setof record AS $BODY$ -- ...