Re: Add big fat caution to pg_restore docs regards partial db restores

On 11/17/2012 12:27:14 AM, Peter Eisentraut wrote:
> On Sun, 2012-09-23 at 21:22 -0500, Karl O. Pinc wrote:
> > Hi,
> >
> > Adds a caution to the pg_restore docs....
> >
> > Against git master.
>
> I'm not sure what you are trying to get at here.  It's basically
> saying,
> if you make an incomplete database restore, you might get an
> incomplete
> database.  Is there any specific failure scenario that we should
> address?

Basically, no.  It's a reminder of all the various sorts
of inconsistencies that might arise from a partial restore,
not just referential integrity but other integrity constraints
that might be enforced by triggers or the application.
Possibly even manual procedural checks.
The idea is that such a list might direct the attention
of the person doing data recovery to overlooked
integrity issues.

I agree, there's no point in a generic warning.
The warning is only useful if it leads the reader
to do a better job of data recovery.

I would summarize slightly differently, an incomplete
restore can lead to an inconsistent database.

---

One criticism of this patch:

Suggestion for --truncate-tables to pg_restore
https://commitfest.postgresql.org/action/patch_view?id=944

was that because it allowed an incomplete restore
you might get an inconsistent database.  If that's
a problem, and at some level it is, then it's a
problem right now and the only
way to address the problem is to help
the data recovery person.  I thought some sort
of brief checklist of kinds of data integrity might
help, put someplace where it would be seen when needed.

Feel free to reject.  I sent in the patch to
try out the idea.  It's a bit crazy, but I didn't
think too crazy to share with the list.

Regards,

Karl <kop@meme.com>
Free Software:  "You don't pay back, you pay forward."                -- Robert A. Heinlein