Re: Re: New data type: uniqueidentifier

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От Dmitry G. Mastrukov
Тема Re: Re: New data type: uniqueidentifier
Дата
Msg-id 3B4228CB.5060907@taurussoft.org
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Ответ на Re: Re: New data type: uniqueidentifier  (Peter Eisentraut <peter_e@gmx.net>)
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Peter Eisentraut wrote:

>Alex Pilosov writes:
>
>>Dmitry's stuff contains both datatype (uniqueidentifier), a function to
>>generate a new object of that type (newid), and a set of functions to
>>implement comparison operators for that type.
>>
>>I don't see anything wrong with that setup, but maybe I'm still missing
>>something?
>>
>
>It would be much simpler if you stored the unique id in varchar or text.
>
Are you sure varchar comparision will be quickly than current 
implementation? Next, varchar will need 36 byte, uniqueidentifier takes 
16. Next, indexing - IMHO current stuff more suitable for indexes. Some 
time ago I saw some stuff which deals with uniqueidentifiers for 
Interbase. It uses your scheme with chars. But it strip "-" from string 
and reverts it to efficiently use indexes (uid sometimes uses 
MAC-address as part of itself, so MAC should go first in string). Weird 
scheme for me!

regards,
Dmitry




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