Subject Re: [firebird-support] Avoiding pessimistic locking
Author Kjell Rilbe
Alan McDonald wrote:

>>>Dmitry Sibiryakov wrote:
>> 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...
>
> definitely - you can even have queries pertaining to different fields in the
> same table and not have conflict
> Alan

OK then, let's assume A has received an updated table of zipcodes from
the postal service and needs to update a customer's zipcode. At the same
time, B has noticed that the customer's street address is misspelt and
wants to correct it.

I guess you could have a street addres to zipcode mapping table, but I
think that would a rather extreme kind of normalization (considering the
mapping would more or less require you to list every single street
address along with its zipcode - it would force you to store MORE data,
not less), and I doubt that you would construct two separate queries -
one for editing the zipcode and another for editing the street address.

I don't think it would be all too difficult to come up with several more
examples.

Kjell
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