Re: Mixing OO and DB

From: Marshall <>
Date: Wed, 5 Mar 2008 07:39:12 -0800 (PST)
Message-ID: <>

On Mar 5, 6:21 am, "Brian Selzer" <> wrote:


> How is that different from denormalization? Updates still have to be made
> in a denormalized schema. Of course, instead of updating one row, it may be
> necessary to update hundreds or even thousands of rows due to the redundancy
> inherent in a denormalized schema. With a materialized view, those updates
> become a refresh of the view, which can happen independent of the update.
> The only substantive difference I can see here is that queries can still be
> satisfied by using the base tables while the materialized view is being
> refreshed, but with a denormalized schema, queries must be held up until
> those hundreds or even thousands of rows are updated, assuming, of course,
> that clients need the absolute latest values.

You make some good points, but there's another one you didn't mention, and that is that manual denormalization is more error prone. You have to get it right everywhere you do an update, and that's not just in code. Also doing it manually means that every relevant programmer has to know the protocol, and follow it without mistake, every time, instead of just declaring the intent and letting the computer handle it.

Marshall Received on Wed Mar 05 2008 - 16:39:12 CET

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