[
https://issues.apache.org/jira/browse/COUCHDB-465?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12745402#action_12745402
]
Robert Newson commented on COUCHDB-465:
---------------------------------------
The utc_random has that issue which is why it's not the default. I don't think
it would make sense to choose utc_random unless you had already planned to keep
your clocks pretty accurately synced. Brian's point, I'm implying, is that
since he *can* arrange that, then if the ids used the clock time he'll get a
nice ordering for identifiers for free. Anyone running couchdb in a data center
could feasibly arrange for ntp synchronization, so I think it's a nice option
for those that understand the consequences.
> Produce sequential, but unique, document id's
> ---------------------------------------------
>
> Key: COUCHDB-465
> URL: https://issues.apache.org/jira/browse/COUCHDB-465
> Project: CouchDB
> Issue Type: Improvement
> Reporter: Robert Newson
> Attachments: couch_uuids.patch, uuid_generator.patch
>
>
> Currently, if the client does not specify an id (POST'ing a single document
> or using _bulk_docs) a random 16 byte value is created. This kind of key is
> particularly brutal on b+tree updates and the append-only nature of couchdb
> files.
> Attached is a patch to change this to a two-part identifier. The first part
> is a random 12 byte value and the remainder is a counter. The random prefix
> is rerandomized when the counter reaches its maximum. The rollover in the
> patch is at 16 million but can obviously be changed. The upshot is that the
> b+tree is updated in a better fashion, which should lead to performance
> benefits.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
