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? Servus Manfred ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend