Re: Object-relational impedence

From: Marshall <>
Date: Wed, 5 Mar 2008 09:16:11 -0800 (PST)
Message-ID: <>

On Mar 3, 8:52 am, JOG <> wrote:


> I was hoping perhaps people might be able to offer
> perspectives on the issues that they have encountered.

Another big difference:

Object oriented languages work in object-at-a-time terms. Even when those objects are collections, if one wants to operate on every object in the collection, one iterates over the objects in the collection and calls methods on those objects one at a time.

The relational model works in set-at-a-time terms. One operates on entire sets at once.

The two don't fit together very well.

One context in which the set-at-a-time approach yields dramatic performance benefits is in distributed programming. It has been my experience that the single biggest performance issue in programming for the datacenter (as opposed to programming for single machines) is the nature of the protocol used across edges in the server graph. The more work the protocol can accomplish in a single message the better. Set-at-a-time thinking, and tools, are necessary.

Marshall Received on Wed Mar 05 2008 - 18:16:11 CET

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