On Mon, Jul 25, 2011 at 9:29 AM, Stefan Heymann <lists@...>wrote:

>
> However, for detecting logical errors in the data tables, you need to
> do a complete restore. Having a switch for GBAK or GFIX that does that
> would help with large databases when run in the night or so.
>

I'm not sure that slowing down the backup to the extent necessary to
validate all constraints is a good trade-off. The backup has to run on the
machine with the database, so it necessarily inhibits garbage collection and
competes with client applications for cycles. My guess is that for a
not-so-heavily constrained database (primary keys for all tables, a few not
null fields in each table) doing a logical validation would double the
backup time.

Buy a $300 machine with a $100 Tb disk that does nothing but restore backups
and report failures.


Good luck,

Ann


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