>uniqueness is never a guaranteed. that is according to the RFC docs.
>uniqueness is never a guaranteed in the sense that there is a tiny
>chance someone of the other side of the planet might generate the same
As much as I learned, it is recommended to give information about "grade of
uniqueness". I think it would be a valuable information, which information
your UUID-generator takes into account, and what the "grade of uniqueness"
(I know of the Windows UUID, which takes the MAC-Address of the included
Ethernet-Card into it's calculation, which may be guaranteed to be unique)
Some more questions about UUIDs and your patch:
a) compatibility of UUIDs -> I have generated a lot of UUIDs via the WIN32
provided function (for the unix-only-people: Windows uses UUIDs all around
its registry, software IDs and on and on). How unique are those UUIDs when
mixed with "your" UUIDs ?
b) I read some time ago about the problems with UUIDs as primary keys in
contrast to serials: serials get produced in ascending order; and often data
which was produced in one timespan is also connected semantically. "near
serial values" are also local within a btree-index; but UUIDs generated in
"near times" are usually spread around the possible bitranges.
(example for sequence of serials: 1 - 2 - 3 - 4 - 5 - 6
example for sequence of UUIDs : 1 - 999919281921843191 - 782 -
that is supposed to affect the locality of the index, and from that also the
performance of the system.
I do not know how valid this information is; so I am asking you for your
feedback; especially since you put a lot of thoughts into this UUID patch.
Maybe you took allready care of this situation when constructing the index
GHUM Harald Massa
persuadere et programmare
Harald Armin Massa
Let's set so double the killer delete select all.
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