Re: Add hint about replication slots when nearing wraparound

On Wed, Dec 27, 2017 at 08:47:20AM +0100, Feike Steenbergen wrote:
> Changed the block from a note to a caution,

Thanks for the new version.

- "You might also need to commit or roll back old prepared transactions.")));
+ "You might also need to commit or roll back old prepared transactions, or drop stale replication slots.")));
Would "or TO drop stale replication slots" be more correct English?

ereport(WARNING,
(errmsg("oldest xmin is far in the past"),
- errhint("Close open transactions soon to avoid wraparound problems.")));
+ errhint("Close open transactions soon to avoid wraparound problems. You might also need to commit or roll back old prepared transactions, or drop stale replication slots.")));

I am not convinced that you need this bit. autovacuum_freeze_max_age can
be set to lower to even lower values than the default.

Still, those are minor comments, so I am marking this patch as ready for
committer to get more input from higher-ups.
--
Michael