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RavenDB Map/Reduce optimizations

· Performance Zone

Download Forrester’s “Vendor Landscape, Application Performance Management” report that examines the evolving role of APM as a key driver of customer satisfaction and business success, brought to you in partnership with BMC.

So I was diagnosing a customer problem, which required me to write the following:

image

This is working on a data set of about half a million records.

I took a peek at the stats and I saw this:

image

You can ignore everything before 03:23, this is the previous index run. I reset it to make sure that I have a clean test.

What you can see is that we start out with a mapping & reducing values. And you can see that initially this is quite expensive. But very quickly we recognize that we are reducing a single value, and we switch strategies to a more efficient method, and we suddenly have very little cost involved in here. In fact, you can see that the entire process took about 3 minutes from start to finish, and very quickly we got to the point where are bottle neck was actually the maps pushing data our way.

That is pretty cool.



See Forrester’s Report, “Vendor Landscape, Application Performance Management” to identify the right vendor to help IT deliver better service at a lower cost, brought to you in partnership with BMC.

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Published at DZone with permission of Ayende Rahien , DZone MVB .

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