Mongo changing document structure query
===

Wondering if anyone has thoughts on the following problem Mongo "schema" change:

We're changing the document in a collection from:


    {"id":60,"measurement":{"steps":1274.0},"date":"2012-05-15T00:00:00Z"}

to:

    {"id":60,"measurement":{"distance":{"steps":1274.0}},"date":"2012-05-15T00:00:00Z"}

In essence, it's changing the definition of measurement from a map[string, double] to a map[string, map[string, double]]

There will be rules to key off such as:
Change steps to distance map key (such as shown above)
Change miles to distance map key
Change minutes to time map key
Etc. etc.

Any thoughts and/or suggestions?

