Features for MongoDB 2.2

Come join us for pizza and a talk about the major features for MongoDb 2.2. We will cover the following features.

Aggregation Framework

The aggregation framework makes it possible to do aggregation operations without needing to use map-reduce. The aggregate (http://docs.mongodb.org/manual/reference/commands/#aggregate) command exposes the aggregation framework, and the db.collection.aggregate() (http://docs.mongodb.org/manual/reference/method/db.collection.aggregate/#db.collection.aggregate) helper in the mongo shell provides an interface to these operations. Consider the following resources for background on the aggregation framework and its use:

TTL Collections

TTL collections remove expired data from a collection, using a special index and a background thread that deletes expired documents every minute. These collections are useful as an alternative to capped collections in some cases, such as for data warehousing and caching cases, including: machine generated event data, logs, and session information that needs to persist in a database for only a limited period of time.

Concurrency Improvements

MongoDB 2.2 increases the server’s capacity for concurrent operations with the following improvements:

DB Level Locking (https://jira.mongodb.org/browse/SERVER-4328) Improved Yielding on Page Faults (https://jira.mongodb.org/browse/SERVER-3357) Improved Page Fault Detection on Windows (https://jira.mongodb.org/browse/SERVER-4538)