On Monday 14 Oct 2002 3:22 pm, Heiko Stoermer wrote: > Hello, > > I'm trying to achieve the following with pl/pgsql in postgres 7.2: > > I need a stored procedure proc() that calculates values for some fields > a = f1() > b = a + f2() > c = b + f3() > and returns the tuple (a,b,c) as a rowtype,
Move to 7.3beta and use table functions, or look at returning a cursor from a function. See the online docs for details. > I know of course that I could write out > SELECT > (f1()) AS a > (f1() + f()) AS b > (f1() + f2() + f3()) AS c ... > in plain SQL and create a view on that, but the problem is that f1(), f2(), > f3() are complex and expensive computations that I want to run only once. > In the example I would call f1() three times, which is inacceptable. Have you looked at marking f1() etc cachable? This means Postgresql will only call the function once for each parameter-set. Only works for functions like: square_root(number) and not next_random_number() -- Richard Huxton ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
