On Fri, 2 Sep 2005 15:51:15 -0400 (EDT), Bruce Momjian <pgman@candle.pha.pa.us> wrote: > * Merge xmin/xmax/cmin/cmax back into three header fields
And don't forget xvac, please. > Before subtransactions, there used to be only three fields needed to > store these four values. ... five values. > This was possible because only the current > transaction looks at the cmin/cmax values. Which is a reason to get rid of cmin/cmax in tuple headers entirely. Once I had a patch based on 7.4 that stored cmin and cmax in backend-local memory. It passed make check and some volume tests, but I felt it was not ready to be applied without any spill-to-disk mechanism. Development stalled when I tried to eliminate xvac as well, which would have required deep cuts into VACUUM code :-( Servus Manfred ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq