Map Reduce Requirements

Jeremiah Peschka jeremiah.peschka at
Mon Aug 22 14:57:07 EDT 2011

You can MR across whatever kind of data you'd like. JSON is typically used because it's very easy to show people how to query JSON and the structure makes sense to many programmers.

To MR across anything else, you'll want a library that will translate your protocol buffers encoded data into objects that can be parsed in either JavaScript or Erlang. That is to say that you'll need a Serialization/Deserialization function to translate between data at rest (protobufs) to data that the MR program can understand.

Since there are protocol buffer libraries for many languages, this should be doable in either JavaScript or Erlang. I don't know of any examples, but it shouldn't be much more difficult than Riak.mapValuesJson - provided that you can find some easy magic to translate objects for you ;)
Jeremiah Peschka - Founder, Brent Ozar PLF, LLC
Microsoft SQL Server MVP

On Aug 22, 2011, at 11:51 AM, bill robertson wrote:

> In order to run a map reduce query v.s. Riak, does the data need to be stored in JSON? If this isn't a requirement, then how would I run a query against data stored in a google protocol buffer format? Is there an example of this somewhere?
> Thanks!
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