Matthew Wakeling wrote on 10.08.2010 17:40:
Currently, I do this in my application by ordering by the number and only using the last value. I imagine that this is something that can be done in the new Postgres 9, with a sorted group by - something like this: SELECT group, LAST(value, ORDER BY number) FROM table GROUP BY group Is this something that is already built in, or would I have to write my own LAST aggregate function?
No. It's built in (8.4) and it's called Windowing functions: http://www.postgresql.org/docs/8.4/static/tutorial-window.html http://www.postgresql.org/docs/8.4/static/functions-window.html SELECT group, last_value(value) over(ORDER BY number) FROM table You don't need the group by then (but you can apply e.g. an ORDER BY GROUP) Thomas -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
