New on PHPMaster.com is the first part of their series about indexing in MongoDB, a method for optimizing your collections to make querying them even faster. They cover the five main types of indexes and situations where they can help.
Indexing is one of the more important concepts of working with MongoDB. A proper understanding is critical because indexing can dramatically increase performance and throughput by reducing the number of full documents to be read, thereby increasing the performance of our application. Because indexes can be bit difficult to understand, this two-part series will take a closer look at them.
They look at the default "_id" index, secondary, compound, multikey and multikey compound indexes. Example documents and results are included as well as some of the options that can be set on the index types to tweak performance. They finish up the article with a look at some of the limitations and considerations to think about when using indexing, including that they cannot be used with regex queries.