Re: Relational Model and Search Engines?

From: Paul <paul_at_test.com>
Date: Tue, 04 May 2004 11:24:23 +0100
Message-ID: <dfKlc.39446$Y%6.5362560@wards.force9.net>

Leandro GuimarÃ£es Faria Corsetti Dutra wrote:

>>Do you think the relational model could efficiently be used as the basis
>>of search engines such as google

>
> Why not?
>
> The relational model is purely logical. Physically the
> implementor is free to use whatever tricks he may wish.

I've seen this argument used a lot and it doesn't seem quite right.

Suppose I have two logical models that do the same thing. For implementing them physically, the best possible algorithm for one might be O(n^2) but for the other it might be O(1).

I can't think of a reasonable example right now, but suppose I have a model that is identical to the relational model except it requires me to factorise a random 1000-digit number before each query (not for any reason, this is just a pathological example).

This is a logical model but clearly any implementation of it will be inferior to a similar implementation of the standard relational model.

So what I'm saying is that a logical model is not totally independent of any physical implementation of it, there may be a upper bound on how efficient it can be.

Paul. Received on Tue May 04 2004 - 05:24:23 CDT