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GUID

Are there enough Globally Unique Identifiers?

There are 2128 possible GUID values. That's 2 multiplied by itself 128 times.

    in scientific notation:
    3.4028236692093846346337460743177e+38

    in decimal notation:
    340,282,366,920,938,463,463,374,607,431,770,000,000*

That's a lot of unique GUIDs!  I don't know what that number is called.

If one billion unique GUIDs are generated every second, that would be
31,536,000,000,000,000 per year, and it would take
10,790,283,070,806,014,188,970* years before there are no more unique values left.

Wow! That's amazing.

 

* This decimal value is not precise because my scientific calculator could only display scientific notation for such a large number.