Database Manual / Aggregation Operations / Reference

Aggregation Database Commands and Methods

Note

For details on a specific command, including syntax and examples, click on the link to the command's reference page.

Aggregation Commands

NameDescription

aggregate

Performs aggregation tasks such as $group using an aggregation pipeline.

count

Counts the number of documents in a collection or a view.

distinct

Displays the distinct values found for a specified key in a collection or a view.

mapReduce

Performs map-reduce aggregation for large data sets.

Aggregation Methods

NameDescription

db.collection.aggregate()

Provides access to the aggregation pipeline.

db.collection.mapReduce()

Performs map-reduce aggregation for large data sets.