Re: Please advise features in 7.1 (SUMMARY)
От | Magnus Naeslund\(f\) |
---|---|
Тема | Re: Please advise features in 7.1 (SUMMARY) |
Дата | |
Msg-id | 017201c059f4$99c57200$020a0a0a@totalmef обсуждение исходный текст |
Ответ на | AW: Please advise features in 7.1 (SUMMARY) (Zeugswetter Andreas SB <ZeugswetterA@wien.spardat.at>) |
Список | pgsql-hackers |
From: "Ross J. Reedstrom" <reedstrm@rice.edu> > On Tue, Nov 28, 2000 at 05:19:45PM +0100, Zeugswetter Andreas SB wrote: > > > I guess it depends on what you're using it for -- disk space > > > is cheap and > > > abundant anymore, I can see some advantages of having it > > > computed only once > > > rather than X times, where X is the number of SELECTs as that > > > could get > > > costly on really high traffic servers.. Costly not so much for simple > > > computations like that but more complex ones. > > > > <snip good arguments about disk space> > > As I said in my original post, my understanding of computed fields may > be in error. If they're computed at SELECT time, to avoid creating table > space, then a VIEW is exacly the right solution. However, it's easy to > come up with examples of complex calculations that it would be useful > to cache the results of, in the table. Then, computing at INSERT/UPDATE > is clearly the way to go. > > So, having _both_ is the best thing. > > Ross > I'm new at this, but the view thing? Isn't that just the same as: create table test2 ( i1 int4, i2 int4); ...insert... select i1,i2,i1+i2 from test2; Magnus -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-Programmer/Networker [|] Magnus NaeslundPGP Key: http://www.genline.nu/mag_pgp.txt -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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