Primary keys and speed

Hello.

I am looking at useing uuid's as primary keys rather than a normal
sequence of numbers.

The uuids are long text strings like so:

7559e648-a29c-11d5-952f-00c026a18838

The reason for useing them is that it's almost gaurenteed that
imported data from another site is going to have a unique identifier.

But I was wondering if this will impact on the speed of the database.

In the long run the application does not need to be blindingly fast as 99%
of the time it is waiting on human interaction.

Any ideas?

--

  Rob Brown-Bayliss
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