Re: Is there possibility btree_redo with XLOG_BTREE_DELETE done between standby_redo and the end of backup

On Wed, May 24, 2017 at 11:18 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> y39chen <yan-jack(dot)chen(at)nokia(dot)com> writes:
>> is there possibility btree_redo with XLOG_BTREE_DELETE info done between
>> standby_redo and the end of backup? I have PostgreSQL 9.3.14 which have
>> some patches to use and easy to happen.
>> ...
>> //inconsistent detected in btree_xlog_delete_get_latestRemovedXid()
>> [26005-59251d35.6595-726087] 2017-05-24 05:42:22.513 GMT < > WARNING:
>> 01000: btree_xlog_delete_get_latestRemovedXid: cannot operate with
>> inconsistent data
>
> This looks a whole lot like a bug we fixed in 9.3.15, cf
>
> https://www.postgresql.org/message-id/flat/DB5PR07MB15416C65687A1EA9AC0D26F8D6E00%40DB5PR07MB1541.eurprd07.prod.outlook.com

To which commit are you referring here? I don't recall any fixes
related to that, and there is nothing in the git history indicating
so.

Still I don't understand how this PANIC code can be reachable with
community code. CountDBBackends() will normally return 0 if
consistency is not reached, and postmaster will block incoming
connections until a consistent state is reached.
--
Michael