Re: [BUGS] Old row version in hot chain become visible after a freeze

Поиск
Список
Период
Сортировка
От Alvaro Herrera
Тема Re: [BUGS] Old row version in hot chain become visible after a freeze
Дата
Msg-id 20170912124136.kgasny22tjf7btdj@alvherre.pgsql
обсуждение исходный текст
Ответ на Re: [BUGS] Old row version in hot chain become visible after a freeze  (Michael Paquier <michael.paquier@gmail.com>)
Список pgsql-bugs
Michael Paquier wrote:
> On Tue, Sep 12, 2017 at 5:22 PM, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
> > Michael Paquier wrote:
> >> On Mon, Sep 11, 2017 at 11:01 PM, Alvaro Herrera
> >> <alvherre@alvh.no-ip.org> wrote:
> >> > (I also threw in a small sleep between heap_page_prune and
> >> > HeapTupleSatisfiesVacuum while testing, just to widen the problem window
> >> > to hopefully make any remaining problems more evident.)
> >>
> >> I am understanding that you mean heap_prepare_freeze_tuple here
> >> instead of heap_page_prune.
> >
> > Hmm ... no, I meant adding a sleep after the page is pruned, before
> > HeapTupleSatisfiesVacuum call that determines the action with regards to
> > freezing.
> 
> Well, I have tested both. With the test case of Dan adding a sleep
> after calling HeapTupleSatisfiesVacuum() helped in increasing the
> window. Of course feel free to correct me.

OK, great, thanks for testing.


> > I bet those are multixact values rather than garbage.  You should see
> > HEAP_XMAX_IS_MULTI in t_infomask in those cases, and the values should
> > be near NextMultiXactId (make sure to checkpoint if you examine with
> > pg_controldata; I think it's easier to obtain it from shmem.  Or you
> > could just use pg_get_multixact_members()).
> 
> Yes, you're right. That's the case. So I guess that I don't have much
> complains about the patch as presented.

Thanks for the confirmation.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


-- 
Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-bugs

В списке pgsql-bugs по дате отправления:

Предыдущее
От: Michael Paquier
Дата:
Сообщение: Re: [BUGS] Old row version in hot chain become visible after a freeze
Следующее
От: digoal@126.com
Дата:
Сообщение: [BUGS] BUG #14812: URI options cann't set with equal char.