Suitability for real-time data processing?

Hi,

I'm looking for a database for a 'real-time' (between 20ms and 1s responses) database for a inventory system.

We're tracking items in a warehouse and will require the ability to read and write around 20,000 items per hour and consult a 0.5 million row table of business rules for each read.

We will be using Compaq Proliant servers (clustered) and NT4.

I've narrowed down the choices to Oracle and SqlServer, but am unable to think of compelling reasons to choose between them. The corporate policy is towards SqlServer, but I'm a little wary of what appears to be relatively poor locking functionality (we'd have to use SqlServer 6.5).

So, why should I choose either database?

Andy

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Andy Hardy