Adam wrote:

> --- In firebird-support@yahoogroups.com, "Thomas" <thomas@...> wrote:
>
>> Hi Eugen,
>>
>> sorry I made the assumption that you had already run GFIX. In my case
>> even after GFIX had been run the problem still persisted.
>>
>
> Before attempting any recovery, you should shutdown the Firebird
> service and burn a copy of the database as-is to CD/DVD. Sometimes
> recovery can go pear shaped, so it is important to have this fallback.
>
> Gfix should first be used, then backup-restore the database to confirm
> this worked.
>
> Often*1 gbak with -g switch can avoid the backup process to avoid
> touching the corrupted record, so that can work also.
>
> If all else fails, you may be able to recover some of the data using a
> data pump tool. I have used IBDatapump with success. It involves
> identifying the corrupted table (gbak will probably have failed on
> it), then identifying the corrupted record. Performing a select with
> an indexed walk, you can probably get the PK or the record that fails.
> Build your where clause to deliberately avoid touching that record and
> see if your select can return the whole table. If so, create a table
> with an identical structure and do a insert into .. select from ..
> query to retrieve the 'good' records. You can then map the new table
> to your old table in a new database using your data pumping tool. Once
> you have a successful data pump, backup and restore to confirm you are
> in the clear.
>
> If your corruption is just an index, you can normally drop the index
> (or constraint) and redeclare it.
>
>
> Adam
>
> *1 By often, I mean relatively often compared to the number of
> corruptions you receive. On reasonable hardware with forced writes
> enabled, and without doing dumb things like file copies of an active
> database file, we have never got corruptions. The only times we have
> seen corruptions is with people not following the rules for handling
> databases or hardware on its last legs.
>
>
>
>
>
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>
> Visit http://www.firebirdsql.org and click the Resources item
> on the main (top) menu. Try Knowledgebase and FAQ links !
>
> Also search the knowledgebases at http://www.ibphoenix.com
>
>
>

Thank you, all replies on this group have been very helpful. Do you have
any idea how a database could get corrupted in this way? My guess is
hardware failure but the machine doesn't show any sign of this.