Alan McDonald wrote:

>> We just use GUIDs here for IDs (as our software runs in a 3-tier
>> environment
>> its better, because we can generate the ID on the client side), and aside
>> from the little problems mentioned by Alan (which aren't real problems) we
>> don't have any complaints.
>>
>
> you're aware that GUIDs provide poor indexing with FB's index trees don't
> you?
> Are you happy with your PK index selectivity?
> Alan
>

Well.. once it's a PK it could be only unique and so forth the best
selectivity available :-)

I think you have written wrong and meant "size" or "compactness" instead
of selectivity.

The number of index entries on a page will be of course small when one
uses a UUID/GUID instead of a integer. I don't have numbers about how
compression goes on a series of UUID/GUID values (since it's "random"
the redundant data should be small and has poor compression). Maybe the
compression ratio is terrible, maybe not so bad as one expects, I don't
know... :-)

I think the OP should give a try and populate a table with UUID/GUID
values and use gstat to see the average size of the index entries
compared to integer fields.

see you !

--
Alexandre Benson Smith
Development
THOR Software e Comercial Ltda
Santo Andre - Sao Paulo - Brazil
www.thorsoftware.com.br