I'm feeling a bit of an idiot for responding to posts that were 5 years ago - oh, well, never mind. And thank heaven's for Paul with his insertion of sanity into the earlier discussion! But now there's something current to comment on.
WayneS (3/24/2015)
Toby Harman (3/23/2015)
...There's no reason to have a GUID as there's no possibility of running out of INT let alone BIGINT.
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In your reply, the implication (emphasized by me above) is that a GUID has a larger capacity than a bigint. The actual number of unique values of a GUID is 2^122; for a bigint data type it is 2^126 (using the full range from the most negative value to the most positive value).
That's quite an achievement, representing 2^126 values using only 64 bits. Have you perhaps multiplied 2^63 by 2 and got 2^126 instead of 2^64?
It reminds me of the famous disc compression scam back in the early 90s (I think - but it may have been late 80s) when an American outfit was going round western Europe selling this wonderful compression firmware which was guaranteed to compress anything, even stuff it had already compressed (no matter how many times). We had a visit from them in ICL West Gorton (I've no idea who arranged for them to be allowed to present their stuff, the guilty person remained anonymous) and were both bemused (how had they go through the defenses) and amused (gales of laughter once they's departed in confusion). What they were selling would have enabled us to represent even more that 2^126 values using only 64 bits.
Tom