Re: performance question: sum values vs. store calculations

Hi.

 If you are sure that 50-100 rows it's all you will ever need -  go for normalized DB ( no data duplication ).  Use views to display totals.
 In that case if performance will suffer - just create a table of  totals, recreate a view to use that table and you application  will remain unchanged.

 Look at Oracle 8i ( materialized views ) - it may worth a try.

 Good luck. Michael.

In article <7qfkq5$si9$1_at_nnrp1.deja.com>,   erik_ostermueller_at_my-deja.com wrote:
> The legacy banking system that we are rewriting stores the results of
many
> calculations in tables. For instance, when a balance is calculated
for an
> account for a new transaction, the new balance is stored on the
record for
> the account. For flexibility and maintainability reasons, we would
prefer
> to store only the atomic transaction data, and derive/calculate the
balance
> (and other calculations) when requested.We know that the tradeoff for
this
> decision is a performance hit, but don't know how big it will be.Each
> calculation will involve about 50-100 records from a total of 1.5
billion
> records. This will be a 24x7 system that expects sub-second response
time.
> Does anyone out there have some experience with this?
>
> Sent via Deja.com http://www.deja.com/
> Share what you know. Learn what you don't.
>

Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't. Received on Tue Aug 31 1999 - 14:42:36 CDT