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The "FUQ" page has been changed by DaveCottlehuber: http://wiki.apache.org/couchdb/FUQ?action=diff&rev1=4&rev2=5 Comment: notes on bulkdocs, uuid advantages == Documents == 1. Why should I generate my own UUIDs? + While CouchDB will generate a unique identifier for the _id field of any doc that you create, there are three reasons why you are in most cases better off generating them yourself. + + * If for any reason you miss the 200 OK reply from CouchDB, and storing the document is attempted again, you would end up with the same document content stored under duplicate _ids. This could easily happen with intermediary proxies and cache systems that may not inform developers that the failed transaction is being retried. + * _ids are are the only unique enforced value within CouchDB so you might as well make use of this. + + * CouchDB stores its documents in a B+ tree. Each additional or updated document is stored as a leaf node, and may require re-writing intermediary and parent nodes. You may be able to take advantage of sequencing your own ids more effectively than the automatically generated ids if you can arrange them to be sequential yourself. + 1. What is the benefit of using the _bulk_docs API instead of PUTting single documents to CouchDB? + + Aside from the HTTP overhead and roundtrip you are saving, the main advantage is that CouchDB can handle the B tree updates more efficiently, decreasing rewriting of intermediary and parent nodes, both improving speed and saving disk space. _bulk_docs also allows you to treat multiple documents in a single phase, either applying all or none of them if so chosen. + 1. Why can't I use MVCC in CouchDB as a revision control system for my docs? == Replication ==
