The CouchDB replication model can be modified for other distributed update models. If the storage engine is enhanced to allow multi-document update transactions, it is possible to perform Subversion-like “all or nothing” atomic commits when replicating with an upstream server, such that any single document conflict or validation failure will cause the entire update to fail. Like Subversion, conflicts would be resolved by doing a “pull” replication to force the conflicts locally, then merging and re-replicating to the upstream server.