Aggregation Commands

Note

For details on specific commands, including syntax and examples,click on the specific command to go to its reference page.

NameDescription
aggregatePerforms aggregation tasks such as group using the aggregation framework.
countCounts the number of documents in a collection or a view.
distinctDisplays the distinct values found for a specified key in a collection or a view.
mapReducePerforms map-reduce aggregation for large data sets.

For a detailed comparison of the different approaches, seeAggregation Commands Comparison.