Re: FSM corruption and standby servers

"Hunley, Douglas" <douglas(dot)hunley(at)openscg(dot)com> writes:
> On Mon, Oct 31, 2016 at 10:38 AM, Tim Goodaire <tgoodaire(at)dyn(dot)com> wrote:
>> I have a question regarding the FSM corruption bug that is fixed in
>> postgresql 9.5.5 (https://wiki.postgresql.org/wiki/Free_Space_Map_Problems)
>> If I don't find any corruption on a master database, is it still possible
>> that there is corruption on the standbys?

> It shouldn't be, iirc. FSMs are only ever created/updated by vacuum, which
> doesn't run on a slave until it is promoted to a master.

The problem is that the WAL data can be wrong in these cases, and since
the standbys only know what they were told in the WAL stream, their images
will be wrong even if the master is valid.

I would have thought that the referenced page is clear enough about
needing to check the standbys; do you think it isn't?

regards, tom lane