Morning Daniel,

See also the Firebird Book by Helen Borrie, Appendix IV Database Repair
How To.

** Always perform validation and recovery attempts using a copy of the
database file(s) and not on the original database file(s). At least you
will have the ability to start again if it goes badly wrong! **

>> I'm especially interested in:
>> - Are there more reasons for a database-file to get corrupted?

http://www.canonbury-services.co.uk/downloads/documents/gm7/Firebird.doc

>> - What exactly does gfix do using the -f -v and the -mend parameters?

-f is -full and causes the -validate to also validate record fragments
on pages instead of the default of checking pages only. (I'm 99% sure
that this is the case!)

-v is -validate and validates the database structure. It also attempts
to fix any problems unless you also specify the -no_update option.

-mend prepares a corrupt database for a backup. It does this by "putting
those corrupt structures out of the way" (Quoting Helen in the Firebird
Book page 935). Basically, the bits that are flagged as corrupt and not
going to be included in your backup!

>> - Is there more than enabling Forced Writes to make a database robust
>> against power-outages, etc.?

Turn off the disc's own hardware cache perhaps. There's a discussion on
this at the moment in the thread "Fbguard - was FB3 ..." on Firebird
Support.

HTH

Cheers,
Norman.

Norman Dunbar
Dunbar IT Consultants Ltd
Tel: 0779 3292 984
Tel: 0773 4531 439

Registered address:
Thorpe House
61 Richardshaw Lane
Pudsey
West Yorkshire
United Kingdom
LS28 7EL

Company Number: 05132767


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