~linuxjedi/drizzle/trunk-bug-738024

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UUID Data Type
==============

The data type uuid stores Universally Unique Identifiers (UUID). Some systems refer to this data type as "globally unique identifier", or GUID, instead. 

This identifier is a 128-bit quantity that is generated by an algorithm designed to make it very unlikely that the same identifier will be generated by anyone else in the world using the same algorithm. The purpose of UUIDs is to enable distributed systems to uniquely identify information without significant central coordination. 

sequence generators, which are only unique within a single database.

A UUID consists of 32 hexadecimal digits, displayed in 5 groups separated by hyphens, in the form 8-4-4-4-12 for a total of 36 characters (32 digits and 4 hyphens). For example:

550e8400-e29b-41d4-a716-446655440000

UUIDs are documented as part of ISO/IEC 11578:1996 "Information technology – Open Systems Interconnection – Remote Procedure Call (RPC)" and more recently in ITU-T Rec. X.667 | ISO/IEC 9834-8:2005. The IETF published Standards Track :rfc:`4122` that is technically equivalent with ITU-T Rec. X.667 | ISO/IEC 9834-8.

Drizzle uses libuuid to generate UUID values.