Alle 20:14, giovedì 11 marzo 2004, hai scritto: > On Thu, Mar 11, 2004 at 09:43:57 +0100, > > Paolo Tavalazzi <[EMAIL PROTECTED]> wrote: > > Alle 19:12, mercoledì 10 marzo 2004, hai scritto: > > > On Wed, Mar 10, 2004 at 18:33:41 +0100, > > > > > > Paolo Tavalazzi <[EMAIL PROTECTED]> wrote: > > > > I don't know what to make, help me please! > > > > > > > > Another question, in 7.4 GROUP BY clause not guarantee the ordering > > > > of result. Can I desable the new group by algorithm to maintain the > > > > coherence whit the programs that I have in production with pg_7.3 > > > > > > GROUP BY never guarenteed an order. That this happened in 7.3 was an > > > implementation detail. If you want a specific order you need to use an > > > ORDER BY clause. > > > > Seeing that GROUP BY in 7.3 required sorting the input data to bring > > group members together, this guaranteed to me also the order of the > > attributes in GROUP BY clause. > > This might be a language difference. You weren't guarenteed (or promised) > that the output would be sorted. It just happened that way because of how > the database implemented the group by. By reading the source code for > that version it would be possible to determine that the output would > always be sorted. However, that could change at any upgrade or if you > switched databases.
You have reason. My deduction comes only from the reading of the code. I thought to have read it also in the postgres documentation,but it is not true. I have seen that the algorithm of group by in 7.4 is various then 7.3,and it seems more efficent. Therefore, i have changed my program to manage the order by clause. Thank you ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]