Hacker News Reader

You can sort of do these operations with couchdb, but you've got to fight against some bad assumptions for this use case of offline edits that could span weeks or months. From https://wiki.apache.org/couchdb/Replication_and_conflicts:

    With CouchDB, you can sometimes get hold of old revisions of a document.
    For example, if you fetch /db/bob?rev=v2b&revs_info=true you'll get a list
    of the previous revision ids which ended up with revision v2b. Doing the
    same for v2a you can find their common ancestor revision. However if the
    database has been compacted, the content of that document revision will
    have been lost. revs_info will still show that v1 was an ancestor, but
    report it as "missing".

That is a very dangerous feature for us. Also, the conflict avoidance algorithm means that users can't work on branches in parallel like in git because couchdb obstructs that workflow with 409 responses. This is a very bad feature when you're collecting data in remote areas and replicating with other databases and don't have the time, battery life, or the expert skills to resolve a "conflict". A database should never have states where it rejects new information.

View on HN

So this gives you a way to introduce conflicts within a single database instance. If you choose to do this instead of PUT, it means you don’t have to write any code for the possibility of getting a 409 response, because you will never get one. Rather, you have to deal with conflicts appearing later in the database, which is what you’d have to do in a multi-master application anyway.