Data Transformation in Ruby
One constant is data in need of transformation. Be it metrics by cohort or grouped counts by occurrence. The data, as stored, only holds semantic value for the application that generated it, other consumers must perform some form of data transformation.
This collects objects created per week.
This same exact concept applied in to large data-sets will require a map-reduce application and will then deal as many objects as you can muster.
That is the beauty of strong building blocks; the basics will get you 70 percent of the way, common sense and adaptability and google will close on the last 30 percent.