Re: Re: [COMMITTERS] pgsql: pg_upgrade: Convert old visibility map format to new format.

On Wed, Apr 27, 2016 at 10:00 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Tue, Apr 26, 2016 at 8:45 PM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
>> On Fri, Mar 11, 2016 at 05:36:34PM +0000, Robert Haas wrote:
>>> pg_upgrade: Convert old visibility map format to new format.
>>>
>>> Commit a892234f830e832110f63fc0a2afce2fb21d1584 added a second bit per
>>> page to the visibility map, but pg_upgrade has been unaware of it up
>>> until now. Therefore, a pg_upgrade from an earlier major release of
>>> PostgreSQL to any commit preceding this one and following the one
>>> mentioned above would result in invalid visibility map contents on the
>>> new cluster, very possibly leading to data corruption. This plugs
>>> that hole.
>>>
>>> Masahiko Sawada, reviewed by Jeff Janes, Bruce Momjian, Simon Riggs,
>>> Michael Paquier, Andres Freund, me, and others.
>>
>> I have tested the current git trees of all supported versions of
>> Postgres in all possible pg_upgrade combinations and they all worked
>> perfectly.

Thank you for testing!
Good news for me.

>
> That's good!
>
> All the commits related to this topic could use extra-careful review
> and testing. If Masahiko-san got anything wrong, or I did, this could
> eat people's data in ways that are very hard to track down.
>

Yeah, we should test this feature in various ways, and I'm going to do so.

Regards,

--
Masahiko Sawada