$limit (aggregation)


Restricts the number of documents that pass through the $limit in the pipeline.

$limit takes a single numeric (positive whole number) value as a parameter. Once the specified number of documents pass through the pipeline operator, no more will. Consider the following example:

    { $limit : 5 }

This operation returns only the first 5 documents passed to it from by the pipeline. $limit has no effect on the content of the documents it passes.


When a $sort immediately precedes a $limit in the pipeline, the $sort operation only maintains the top n results as it progresses, where n is the specified limit, and MongoDB only needs to store n items in memory. This optimization still applies when allowDiskUse is true and the n items exceed the aggregation memory limit.

Changed in version 2.4: Before MongoDB 2.4, $sort would sort all the results in memory, and then limit the results to n results.