Question

I was reading ‘CouchDB: The Definitive Guide’ and I was confused by this paragraph:

For demoing purposes, having CouchDB assign a UUID is fine. When you write your first programs, we recommend assigning your own UUIDs. If your rely on the server to generate the UUID and you end up making two POST requests because the first POST request bombed out, you might generate two docs and never find out about the first one because only the second one will be reported back. Generating your own UUIDs makes sure that you’ll never end up with duplicate documents.

I thought that uuids (specifically the _id) were saved only when the document creation was successful. That is, when I “post” an insert request for a new document, the _id is generated automatically. If the document is saved then the field is kept, otherwise discarded. Is that not the case?

Can you please explain what is the correct way to generate _id fields in CouchDB?

Answer 1

I think this quote is not really about UUIDs but about using PUT (which is idempotent) instead of POST.

Check this thread for more information : Consequences of POST not being idempotent (RESTful API)