I need to match part of an _id that was automatically generated on the server. This is for an administration tool letting the administrator specify part of an id to make things more usable for them. I don't care what the actual solution is, but there is currently no way to do this without visiting every row from a client.

One example way would be using regex:

find({_id: /.ab3c94./})

Currently regexes do not work against object id.