Subject Re: [firebird-support] Avoiding pessimistic locking
Author Kjell Rilbe
Dmitry Sibiryakov wrote:

> On 7 Oct 2005 at 8:09, Kjell Rilbe wrote:
>>A is updating the order record because she got a notification that the
>>goods has been delivered while B is updating it because he's just
>>mailed the invoice, and C is updating it because the customer just
>>called to say that she will be returning one of the items because it
>>was damaged?
> It smells like denormalized DB structure.
> Can't say about delivery confirmation, but history of sent invoices
> and accepted reclamations I'd put into separate tables...

Granted, but the point is that no matter how normalized your DB is it's
not unthinkable that different users need to independently and
simultaneously edit different aspects of a record, and that the
application has to handle this without data loss, even if it only
happens once every twentythird year.

Kjell Rilbe
Adressmarknaden AM AB
E-post: kjell.rilbe@...
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