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Robert Newson commented on COUCHDB-465: --------------------------------------- I just noticed that Paul's implementation is not as Brian described; the suffix is always random with no guarantee the id N+1 is strictly higher than id N; + list_to_binary(Prefix ++ couch_util:to_hex(crypto:rand_bytes(9))). In practise it just means that id's generated in the same millisecond are randomly ordered. Does that matter? > 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.