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From Robert Newson <rnew...@apache.org>
Subject Re: are auto-generated uuids unique across server-instance
Date Thu, 08 Nov 2012 18:21:16 GMT
Hi,

Here's the pertinent information on the various UUID algorithms CouchDB
supports;

[uuids]
; Known algorithms:
;   random - 128 bits of random awesome
;     All awesome, all the time.
;   sequential - monotonically increasing ids with random increments
;     First 26 hex characters are random. Last 6 increment in
;     random amounts until an overflow occurs. On overflow, the
;     random prefix is regenerated and the process starts over.
;   utc_random - Time since Jan 1, 1970 UTC with microseconds
;     First 14 characters are the time in hex. Last 18 are random.
;   utc_id - Time since Jan 1, 1970 UTC with microseconds, plus
utc_id_suffix string
;     First 14 characters are the time in hex. uuids/utc_id_suffix string
value is appended to these.

The default is "sequential".

B.


On 8 November 2012 18:13, Mark Hahn <mark@hahnca.com> wrote:

> http://en.wikipedia.org/wiki/Universally_unique_identifier
>
> On Thu, Nov 8, 2012 at 2:31 AM, Andrey Kuprianov <
> andrey.kouprianov@gmail.com> wrote:
>
> > It's a uuid. It's unique wherever
> >
> >
> > On Thu, Nov 8, 2012 at 6:32 PM, svilen <az@svilendobrev.com> wrote:
> >
> > > hi
> > > are auto-generated uuids (when doc is saved without assigned id)
> > > unique across server-instance, or only within the database?
> > >
> > > i.e. can i take a doc from one database and write
> > > it as-is-without-the-_rev into another database?
> > > can that become a problem?
> > >
> > > ciao
> > > svil
> > >
> > > www.notionery.com
> > > www.svilendobrev.com
> > >
> >
>

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