Over a million developers have joined DZone.

Mongoid Collection Snapshot - Great for MapReduce

· Database Zone

Learn NoSQL for free with hands-on sample code, example queries, tutorials, and more.  Brought to you in partnership with Couchbase.

Another fine open-source contribution from @aaw, mongoid_collection_snapshot: easy maintenance of collections of processed data in MongoDB with the Mongoid ODM.

 

https://github.com/aaw/mongoid_collection_snapshot


This turned out to be extremely useful in many map-reduce scenarios where we do lengthy computations that output data that is used as a complete and consistent set. For example, calculating average prices across ranges of items (the example in the documentation). Another good use can be for tags stored as arrays of strings – you want to know how many items are tagged with a given entry. We can now take my incremental tag count map-reduce and replace it with a much more trivial implementation that uses this gem.

The Getting Started with NoSQL Guide will get you hands-on with NoSQL in minutes with no coding needed. Brought to you in partnership with Couchbase.

Topics:

Published at DZone with permission of Daniel Doubrovkine. See the original article here.

Opinions expressed by DZone contributors are their own.

The best of DZone straight to your inbox.

SEE AN EXAMPLE
Please provide a valid email address.

Thanks for subscribing!

Awesome! Check your inbox to verify your email so you can start receiving the latest in tech news and resources.
Subscribe

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}