Hi, Mischa, On Tue, 14 Sep 2004 22:58:20 GMT Mischa Sandberg <[EMAIL PROTECTED]> wrote:
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> Googling 'upsert' (an Oraclism, I believe) will get you hits on Oracle > and DB2's implementation of MERGE, which does what AMOUNTS to what is > described below (one mass UPDATE...FROM, one mass INSERT...WHERE NOT > EXISTS). > > No, you shouldn't iterate row-by-row through the temp table. > Whenever possible, try to do updates in one single (mass) operation. > Doing it that way gives the optimizer the best chance at amortizing > fixed costs, and batching operations. But when every updated row has a different value for the column(s) to be updated, then I still have to use one update statement per row, which I expect to be faster when done via a stored procedure than having the whole client-server roundtrip including parsing every time. Or did I miss some nice SQL statement? Have a nice day, Markus -- markus schaber | dipl. informatiker logi-track ag | rennweg 14-16 | ch 8001 zürich phone +41-43-888 62 52 | fax +41-43-888 62 53 mailto:[EMAIL PROTECTED] | www.logi-track.com ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
