A beginner’s guide to MongoDB performance turbocharging

Introduction This is the second part of our MongoDB time series tutorial, and this post will be dedicated to performance tuning. In my previous post, I introduced you into our virtual project requirements. In short, we have 50M time events, spanning from the 1st of January 2012 to the 1st of January 2013, with the following structure: We’d like to aggregate the minimum, the maximum, and the average value as well as the entries count for the following discrete time samples: all seconds in a minute all minutes in an hour all… Read More

How to fetch entities multiple levels deep with Hibernate

Introduction It’s quite common to retrieve a root entity along with its child associations on multiple levels. In our example, we need to load a Forest with its Trees and Branches and Leaves, and we will try to see have Hibernate behaves for three collection types: Sets, Indexed Lists, and Bags.