* Tom Lane wrote:
> Karsten Desler <kd@link11.de> writes:
> > I have a smallish postgres database that segfaults everytime when I try to
> > access a certain row in a certain column.
>
> Looks like a corrupted-data issue to me. It might be interesting to
> dump the page with pg_filedump and see if there's any apparent pattern
> to the damage.
Thanks, I'll try to play with pg_filedump later tonight.
I've never had problems with this (and many more) postgres servers regarding
corruption of on disk data structures and I'm perfectly fine with chalking it
up to hardware problems.
I don't know much about the postgres architecture and I don't know if bounds
checking on-disk values on a read makes a lot of sense since usually one
should be able to assume that there are no randomly flipped bits; but it
would've been nice to have a sensible log entry as to what really
happened.
Anyway, for future reference: Assuming that this is the only corruption,
can I just UPDATE (or DELETE and reINSERT) the offending entry (maybe with a
following REINDEX/VACUUM?) or do I need to restore a backup?
If possible, I'd prefer the UPDATE solution, of course, since it can be done
without any downtime.
Keep up the good work.
Best regards,
Karsten Desler