Re: Confusing message on startup after a crash while recovering

Tom Lane wrote:
> "Florian G. Pflug" <fgp(at)phlo(dot)org> writes:
>> I'd suggest that the text is changed to something along the line of:
>> "database system was interrupted while in recovery at ...
>> If this has occurred more than once some data may be corrupted and
>> you may need to restore from the last backup."
>
> It seems the real problem is that it's not specifying *which* data is
> probably corrupted. Maybe:
>
> HINT: If recovery fails repeatedly, it probably means that the recovery log
> data is corrupted; you may have to restore from your last full backup.

IMHO that wording would be fine too - the important points for me is to
clearly state that corrupted data is maybe the _cause_ of the crash, and
not the _effect_ of the crash. And for the sake of consistency, the
message for abort-during-recovery and abort-during-archivelog-replay
should be similar.

> Also, do we want to suggest use of pg_resetxlog in the message?
I'd rather add some documentation of how to use pg_resetxlog to the
manual if it's not already there, any maybe reference that chapter in
a HINT message. In that manual chapter you can warn about the dangers
of pg_resetxlog, and put in an advice to backup the database before
using it. I think such a warning is important, because any documentation
of pg_resetxlog is targeted at users know are not familiar with postgres
internals, and those users are likely to shoot themselves in their foot
if you point them to pg_resetxlog.

greetings, Florian Pflug