Aggregation Pipeline Builder
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New in version 1.14.0
The Aggregation Pipeline Builder in MongoDB Compass provides the ability to create aggregation pipelines to process data. In aggregation pipelines, documents in a collection or view pass through stages where MongoDB Compass processes them into a set of aggregated results. You can change the stages and results to suit your needs.
To start building an aggregation pipeline for a collection or view, choose the collection and click the Aggregations tab. A blank aggregation pipeline displays. The Preview of Documents in the Collection section of the Aggregations view displays 20 documents sampled from the current collection.
$out stage is not available if you are connected to a
Create an Aggregation Pipeline
Add an aggregation pipeline stage.
In the aggregation pipeline pane in the lower-left corner, click the Select... dropdown and select the aggregation pipeline stage to use for the first stage of the pipeline:
Add additional pipeline stages.
Click Add Stage to add additional aggregation stages below your last aggregation stage. Repeat steps 1 and 2 for each additional stage.
The toggle to the right of the name of each pipeline stage dictates whether that stage is included in the pipeline. Toggling a pipeline stage also updates the pipeline preview, which reflects whether or not that stage is included.
Save a Pipeline
You can save a pipeline so that you can find it later. If you load a saved pipeline, you can change it without changing the original saved copy. You can also create a view from your pipeline results.
To save your pipeline:
Open a Saved Pipeline
Click the Folder icon at the top left of the pipeline builder.
Hover over the pipeline you want to open and click Open.
In the modal, click Open Pipeline.
Starting in MongoDB Compass 1.31, you can view your saved queries and aggregation pipelines on the My Queries view once connected to your cluster.
To learn more, see viewing saved aggregations for details.
Set the Documents Limit or Auto Preview Documents
Use the toggles at the top of the pipeline builder to set the limit on the number of sampled documents or to enable auto preview.
(Recommended) When enabled, limits input documents passed to
When enabled, Compass automatically updates the preview documents pane to reflect the results of each active stage as the pipeline progresses.
View or Change Pipeline Settings
To view and change pipeline settings:
Click the gear icon at the upper right of the pipeline builder to open the Settings panel.
Change any of the following pipeline settings.OptionDescriptionDefaultWhen enabled, adds helper comments to each stage.EnabledNumber of documents to show in the preview.20When Sample Mode is enabled, specifies the number of documents passed to
$bucketAutostages. Lower limits improve pipeline running time, but may miss documents.100000
Click Apply to save changes and close the Settings panel.
Explain Plan for Pipelines
Use the Explain button to view the explain plan that helps you understand the performance of your pipelines. You can view the explain plan at any point while creating or editing your pipeline.
To view your pipeline explain plan, click Explain in the right corner of your pipeline toolbar.
Your results are presented in this format:
Specify Custom Collation
Use custom collation to specify language-specific rules for string comparison, such as rules for letter case and accent marks.
To specify a custom collation:
Click More Options in the top right corner of the pipeline builder.
Enter your collation document.
Export Aggregation Results
To export results from your aggregation pipeline:
Connect to the deployment containing the collection you wish to export data from.
To learn how to connect to a deployment, see Connect to MongoDB.
Navigate to your target collection.
You can either select the collection from the Collections tab or click the collection in the left-hand pane.
Create an aggregation pipeline and run for results.
To learn how to create an aggregation pipeline, see Create an Aggregation Pipeline.
Choose the appropriate file type.
Under Select Export File Type, select either JSON or CSV. If you select JSON, your data is exported to the target file as an array of JSON objects.
Under Output, choose where to export the file to.
Create a View from Pipeline Results
Creating a view from pipeline results does not save the pipeline itself.
To create a view from your pipeline results:
Click the arrow next to the Save button at the top of the pipeline builder.
Click Create a View.
Enter a name for your view.
Compass creates a view from your pipeline results in the same database where the pipeline was created.
In this example, you create and run a pipeline for a collection with airline data. You can download this dataset from the following link: air_airlines.json.
For instructions on importing JSON data into your cluster, see Import Data
into a Collection. This example assumes you have the data in the
Connect to a database deployment. For information on how to connect to a database deployment, see Connect via Compass.
exampledatabase where the
Create the Pipeline
The following pipeline has two aggregation stages:
$groupstage groups documents by their
country. The stage also adds a new
flightCountfield containing the number of documents in each group.
$matchstage filters documents to return documents with a
flightCountvalue greater than or equal to
Run the Pipeline.
Click Run at the top right of the pipeline builder.
The pipeline returns documents, as shown in the following abbreviated example: