Partial indexes allow you to create an index that only includes documents in a collection that conform to a filter expression. These indexes can be much smaller, cutting down index overhead in storage space and update time, and by matching against the filter criteria, queries can use this slimmed-down index and run much faster. This is one of the new lightweight “schema where you need it” features we’re bringing to MongoDB in 3.2. The idea for this feature came from discussion with our users who are accustomed to it from relational databases like PostgreSQL, which introduced the feature in version 7.2. With partial indexes, you use your knowledge of your application to adjust the space/time tradeoff you make when creating indexes to fit your needs.

The aggregation framework is one my favorite tools in MongoDB. Its a clean way to take a set of data and run it through a pipeline of steps to modify, analyze, and process data.

At MongoDB World, one of the features we talked about that is coming in MongoDB 3.2 is $lookup. $lookup is an aggregation stage that lets you run a query on a different collection and put the results into a document in your pipeline. This is a pretty powerful feature that we’ll talk more about in a later post.

I’ve written a Python program to do something fancy with JIRA that I couldn’t get using built-in facilities. You already get notifications from Jira about the tickets you personally care about, based on your notification settings. My tool will give you, additionally, an hourly email in your inbox summarizing all the changes in projects you care about, skipping the the ones you already got direct notifications of. Not only that, but it will make sure that you only ever have one of these summaries in your inbox, by consolidating them when a new summary is generated. It’s only at version 0.2 at the moment, but I’m opening it up today and hopefully some of you will find it useful. Over time, I hope we can polish it some more.

I get a lot of email. I used to think I got a lot of email, but that was before 10gen. Maybe one day I’ll remember writing this and laugh because comparatively today’s load is light. I hope not, because that thought is frankly scary.

There are a number of programs I’ve written to help me deal with email. One of them is less about helping me, and more about letting the people around me know that I don’t have a special desire to ignore them.