On Wed, Apr 14, 2010 at 06:06:59PM +0200, Pavel Stehule wrote: > I don't understand well. Why you don't use a function date_trunc(), > > select date_trunc('week', created), count(*) > from price > group by date_trunc('week', created)
Because if a price doesn't change for more than a week, then some weeks will have bad statistical distribution (i.e not including prices which only have their 'modified' updated). So I (think I) need to (1) generate the weeks separately and (2) average prices that are current for each week. But I could be missing something obvious. -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql