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From Mark Hahn <m...@hahnca.com>
Subject Re: are auto-generated uuids unique across server-instance
Date Thu, 08 Nov 2012 18:36:13 GMT
I use utc_random.  It is really useful.  Easy to sort by creation date.
 And you can even extract the creation date from the _id and save a field.

On Thu, Nov 8, 2012 at 10:21 AM, Robert Newson <rnewson@apache.org> wrote:

> 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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