Re: Re: New data type: uniqueidentifier

On Mon, 2 Jul 2001, Thomas Swan wrote:

> Peter Eisentraut wrote:
>
> >Dmitry G. Mastrukov writes:
> >
> >>I've developed new data type for PostgreSQL - unique identifier - 128-bit
> >>value claims to be unique across Universe. It depends on libuuid from
> >>e2fsprogs by Theodore Ts'o.
> >>
> >
> >ISTM that this should be a function, not a data type.
> >
> I'd second the function idea: function uuid( ) returns an int8 value;
> don't create a bazillion datatypes. Besides, 128 bit numbers are 7 byte
> integers. PostgreSQL has an int8 (8 byte integer) datatype. While I
> like the UUID function idea, I'd recommend a better solution to creating
> an "unique" identifier. Why not create a serial8 datatype: int8 with an
> int8 sequence = 256bit "unique" number. {Yes, I know I'm violating my
> first sentence.} Then, you'd have the same thing (or better) AND your
> not relying on randomness.

I don't think you know what UUID is. It is NOT just a unique randon
number. There are specific rules for construction of such number, specific
rules for comparison of numbers (no, its not bit-by-bit), thus a datatype
is most appropriate answer.

-alex