Aggregation Commands

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Note

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

Name	Description
`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.

Name	Description
`db.collection.aggregate()`	Provides access to the aggregation pipeline.
`db.collection.mapReduce()`	Performs map-reduce aggregation for large data sets.