Performance Measured and Tuned Batch Processing of Records with Blocks in Rails. EachInBatches (Originally BolingForBatches) NOTE: I am resurrecting this code because I still have this recurring need, and Rail’s native batching doesn’t cut mustard. It is some of my most ancient code, and it isn’t pretty, but I hope to improve it over time. I often need to execute really large computations on really large data sets. I usually end up writing a rake task to do it, which calls methods in my models.