On Thu, Mar 1, 2012 at 10:27 AM, Alessandro Gagliardi <alessandro@xxxxxxxx> wrote: > Now, I want to reduce that data to get the last activity that was performed > by each user in any given hour. It should fit into a table like this: > How about: 1) Create an expression based index on date_trunc('hour', hr_timestamp) 2) Create a view on that showing the last value 3) If you want to throw away the data use CREATE TABLE AS on the results of the view. You may also want to investigate window functions. -p -- Peter van Hardenberg San Francisco, California "Everything was beautiful, and nothing hurt." -- Kurt Vonnegut -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance