On 13 October 2014 10:05, Petr Jelinek <petr@2ndquadrant.com> wrote:
>> I worked bit on this patch to make it closer to committable state.
> Here is updated version that works with current HEAD for the October
> committfest.
I've reviewed this and it looks good to me. Clean, follows existing
code neatly, documented and tested.
Please could you document a few things
* ExtendCommitTS() works only because commit_ts_enabled can only be
set at server start.
We need that documented so somebody doesn't make it more easily
enabled and break something.
(Could we make it enabled at next checkpoint or similar?)
* The SLRU tracks timestamps of both xids and subxids. We need to
document that it does this because Subtrans SLRU is not persistent. If
we made Subtrans persistent we might need to store only the top level
xid's commitTS, but that's very useful for typical use cases and
wouldn't save much time at commit.
-- Simon Riggs http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services