Re: [bugfix] commit timestamps ERROR on lookup of FrozenTransactionId

Craig Ringer <craig@2ndquadrant.com>

From: Craig Ringer <craig@2ndquadrant.com>
To: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2016-11-23T13:02:31Z
Lists: pgsql-hackers

Attachments

On 23 November 2016 at 20:58, Craig Ringer <craig@2ndquadrant.com> wrote:
> Hi all
>
> Today I ran into an issue where commit timestamp lookups were failing with
>
>         ERROR: cannot retrieve commit timestamp for transaction 2
>
> which is of course FrozenTransactionId.
>
> TransactionIdGetCommitTsData(...) ERRORs on !TransactionIdIsNormal(),
> which I think is wrong. Attached is a patch to make it return 0 for
> FrozenTransactionId and BootstrapTransactionId, like it does for xids
> that are too old.
>
> Note that the prior behaviour was as designed and has tests to enforce
> it. I just think it's wrong, and it's also not documented.
>
> IMO this should be back-patched to 9.6 and, without the TAP test part, to 9.5.

Updated to correct the other expected file, since there's an alternate.


-- 
 Craig Ringer                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

Commits

  1. Fix commit_ts for FrozenXid and BootstrapXid