On 05-27-2011 22:28, Bob Melson wrote: > So, will SOMEbody please 'splain me this thing called a > globally/universally unique ID and its place in the grand scheme of > things? UUID / GUID were not created by genealogists to identify multiple definitions of a person. They were created by computer types to distinguish between two things that can't be told apart any other way. Kind of like a serial number. A checksum on the other hand, is a way to be almost certain that two items have or don't have identical contents without actually comparing byte by byte. Or to verify that the item has or hasn't changed since the checksum was generated. If a record on your machine and one on my machine have identical UUIDs, then either one of them was copied from the other (NOT independently generated) or one of us (or our software) was naughty and altered a UUID. If the UUIDs match and the items do not, then either someone changed the UUID on another record, or changed the record without giving it a new UUID. Well-behaved software will not gratuitously change a UUID. But lots of programs will fail to create a new UUID when the item ceases to be a copy of the other. That, in my opinion makes them useless for genealogy. But they were never intended to be some magic way of automatically identifying independently generated records as being representations of the same entity. -- Wes Groleau There are two types of people in the world … http://Ideas.Lang-Learn.us/barrett?itemid=1157