On 31 January 2012 14:24, Robert Haas <robertmh...@gmail.com> wrote: > I think you're trying to muddy the waters. Heikki's implementation > was different than yours, and there are some things about it I'm not > 100% thrilled with, but it's fundamentally the same concept. The new > idea you're describing here is something else entirely. Instead of > focusing on a technical critique of one implementation vs. another > (out of the three we have to choose from), you're looking at cramming > more optimizations into the implementation you prefer. I'm pretty > sure that Heikki's implementation could support that optimization, > too, if we actually want to do it that way. But there might be good > reasons not to do it that way: for example, every transaction commit > will have to bump the CLOG page LSN, which will delay setting hint > bits on other transactions on the page in cases where they can now be > set immediately. In any event, trying to slip it into the group > commit patch will serve only to prevent it from getting the separate > scrutiny which it doubtless deserves.
Well, I also think it deserves separate scrutiny, but it's not as if it can be reasonably argued that it can be isolated from 1 of those 3 implementations. Our immediate goal is to produce a benchmark of a new patch, that operates on the same fundamental principle as the original patch, though with a much reduced code footprint. We then have a reasonable basis for comparison: The original benchmark (or possibly a new benchmark on the original patch, which has seemingly identical performance characteristics to Heikki's anyway), and the new patch. -- Peter Geoghegan http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training and Services -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers