- sequential: 26 hex character random prefix, followed by 6 hex characters of sequence, which is incremented by random amounts. When the 6 character sequence overflows, a new random prefix is chosen. There are no guarantees of ordering, but most inserted documents will be sequentially ordered. This improves insert speed as most B-tree edits do not happen randomly. Also, if the documents are likely to be accessed sequentially, this improves access speeds.
- random: 32 hex characters generated completely at random.
- utc_random: First 14 hex characters are microseconds since Jan 1, 1970 (Unix epoch), followed by 18 random hex characters.
To Update the setting ew can use REST api of the couchDB,
[rozaydin@RO ~]$ curl -X PUT http://localhost:5984/_config/uuids/algorithm -d '"sequential"'
As you can see CouchDB responds with the old algorithm it was using to generate the _id fields prior the update. The same configuration should be able to be done using local.ini file however i failed to find the proper name for the setting if you know how please leave a comment :)