Creating a background and foreground index in the shell

In our previous recipe, we looked at how to analyze the queries, how to decide what index needs to be created, and how to create indexes. This, by itself, is straightforward and looks reasonably simple. However, for large collections, things start getting worse as the index creation time is large. The objective of this recipe is to throw some light on these concepts and avoid these pitfalls while creating indexes, especially on large collections.

Getting ready

For the creation of indexes, we need to have a server up and running. A simple single node is what we need. Refer to the Installing single node MongoDB recipe from Chapter 1, Installing and Starting the Server for instructions on how to start the server.

Start connecting two shells to the server by just typing mongo from the operating system shell. Both of them will, by default, connect to the test database.

Our test data for zip codes is too small to demonstrate the problem faced...