On Sat, Sep 03, 2005 at 10:59:31AM +0200, Manfred Koizar wrote: > On Fri, 2 Sep 2005 20:41:48 -0400 (EDT), Bruce Momjian > <pgman@candle.pha.pa.us> wrote: > >> Once I had a patch based on 7.4 that stored cmin and cmax in > >> backend-local memory. > > >Interesting idea, but how would you record the cmin/xmin values without > >requiring unlimited memory? > > That's exactly the reason for not sending it to -patches. Without > spilling to disk this is just not ready for real life. The problem is > that -- unlike other data structures that build up during a > transaction, e.g. trigger queues -- cmin/cmax lookup requires random > access, so we'd need some form of tree or hash. Unfornunately I never > got beyond brainstorming :-( > > BTW, is there anything else that'd need spilling to disk during long > transactions?
Yes, the queue of pending deferred triggers. -- Alvaro Herrera -- Valdivia, Chile Architect, www.EnterpriseDB.com "El hombre nunca sabe de lo que es capaz hasta que lo intenta" (C. Dickens) ---------------------------(end of broadcast)--------------------------- TIP 1: 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