On Thu, May 28, 2015 at 11:34 AM, Sawada Masahiko <sawada.m...@gmail.com> wrote: > On Thu, Apr 30, 2015 at 8:07 PM, Sawada Masahiko <sawada.m...@gmail.com> > wrote: >> On Fri, Apr 24, 2015 at 11:21 AM, Sawada Masahiko <sawada.m...@gmail.com> >> wrote: >>> On Fri, Apr 24, 2015 at 1:31 AM, Jim Nasby <jim.na...@bluetreble.com> wrote: >>>> On 4/23/15 11:06 AM, Petr Jelinek wrote: >>>>> >>>>> On 23/04/15 17:45, Bruce Momjian wrote: >>>>>> >>>>>> On Thu, Apr 23, 2015 at 09:45:38AM -0400, Robert Haas wrote: >>>>>> Agreed, no extra file, and the same write volume as currently. It would >>>>>> also match pg_clog, which uses two bits per transaction --- maybe we can >>>>>> reuse some of that code. >>>>>> >>>>> >>>>> Yeah, this approach seems promising. We probably can't reuse code from >>>>> clog because the usage pattern is different (key for clog is xid, while >>>>> for visibility/freeze map ctid is used). But visibility map storage >>>>> layer is pretty simple so it should be easy to extend it for this use. >>>> >>>> >>>> Actually, there may be some bit manipulation functions we could reuse; >>>> things like efficiently counting how many things in a byte are set. >>>> Probably >>>> doesn't make sense to fully refactor it, but at least CLOG is a good source >>>> for cut/paste/whack. >>>> >>> >>> I agree with adding a bit that indicates corresponding page is >>> all-frozen into VM, just like CLOG. >>> I'll change the patch as second version patch. >>> >> >> The second patch is attached. >> >> In second patch, I added a bit that indicates all tuples in page are >> completely frozen into visibility map. >> The visibility map became a bitmap with two bit per heap page: >> all-visible and all-frozen. >> The logics around vacuum, insert/update/delete heap are almost same as >> previous version. >> >> This patch lack some point: documentation, comment in source code, >> etc, so it's WIP patch yet, >> but I think that it's enough to discuss about this. >> > > The previous patch is no longer applied cleanly to HEAD. > The attached v2 patch is latest version. > > Please review it.
Attached new rebased version patch. Please give me comments! Regards, -- Sawada Masahiko
000_add_frozen_bit_into_visibilitymap_v3.patch
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