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This page shows how to create and query a time series collection, with code examples.

You can only create time series collections on a system with featureCompatibilityVersion set to 5.0 or greater.

Create the collection using either the db.createCollection() method or the create command. For example:

Set the timeField to the field that contains time data, and the metaField to the field that contains metadata:

Define the time interval for each bucket of data using one of the two approaches below. For more detailed information, see Set Granularity for Time Series Data.

After creation, you can modify granularity or bucket definitions using the collMod method. However, you can only increase the timespan covered by each bucket. You cannot decrease it.

Define a granularity field:

OR

In MongoDB 6.3 and higher, you can define bucketMaxSpanSeconds and bucketRoundingSeconds fields. Both values must be the same:

Optionally, set expireAfterSeconds to expire documents when the value of the timeField is at least that old:

A time series collection includes the following fields:

Required. The name of the field which contains the date in each time series document. Documents in a time series collection must have a valid BSON date as the value for the timeField.

Optional. The name of the field which contains metadata in each time series document. The metadata in the specified field should be data that is used to label a unique series of documents. The metadata should rarely, if ever, change.

The name of the specified field may not be _id or the same as the timeseries.timeField. The field can be of any type.

Optional. Do not use if setting bucketRoundingSeconds and bucketMaxSpanSeconds.

Possible values are seconds (default), minutes, and hours.

Set granularity to the value that most closely matches the time between consecutive incoming timestamps. This improves performance by optimizing how MongoDB stores data in the collection.

For more information on granularity and bucket intervals, see Set Granularity for Time Series Data.

Optional. Use with bucketRoundingSeconds as an alternative to granularity. Sets the maximum time between timestamps in the same bucket.

Possible values are 1-31536000.

New in version 6.3.

Optional. Use with bucketMaxSpanSeconds as an alternative to granularity. Must be equal to bucketMaxSpanSeconds.

When a document requires a new bucket, MongoDB rounds down the document's timestamp value by this interval to set the minimum time for the bucket.

New in version 6.3.

Other allowed options that are not specific to time series collections are:

storageEngine

indexOptionDefaults

collation

writeConcern

comment

db.createCollection() and create.

Each document you insert should contain a single measurement. To insert multiple documents at once, issue the following command:

To insert a single document, use the db.collection.insertOne() method.

To learn how to optimize inserts for large operations, see Optimize Inserts.

You query a time series collection the same way you query a standard MongoDB collection.

To return one document from a time series collection, run:

Example output:

For additional query functionality, use an aggregation pipeline such as:

The example aggregation pipeline groups all documents by the date of the measurement and then returns the average of all temperature measurements that day: