{"id":104932,"date":"2025-01-27T14:45:26","date_gmt":"2025-01-27T14:45:26","guid":{"rendered":"https:\/\/www.red-gate.com\/simple-talk\/?p=104932"},"modified":"2025-01-27T15:41:18","modified_gmt":"2025-01-27T15:41:18","slug":"creating-time-series-collections-in-mongodb","status":"publish","type":"post","link":"https:\/\/www.red-gate.com\/simple-talk\/databases\/nosql\/mongodb\/creating-time-series-collections-in-mongodb\/","title":{"rendered":"Creating Time Series Collections in MongoDB"},"content":{"rendered":"

This article is part of Robert Sheldon's continuing series on Mongo DB. To see all of the items in the series, click here<\/a>.<\/strong><\/p>\n\n\n\n\n

Throughout this series, I\u2019ve introduced you to different features in MongoDB and provided examples to help demonstrate how the database system works. The examples have all been based on conventional collections, the type that MongoDB creates by default. However, MongoDB also supports other types of collections, including the time series collection, which can benefit many of today\u2019s event-driven workloads.<\/p>\n\n\n\n

The documents in a time series collection represent a sequence of data points, with each document recording an event at a specific point of time. For example, a machine sensor might generate temperature readings that are transformed into individual documents and stored in a time series collection.<\/p>\n\n\n\n

A time series collection is optimized to handle these types of documents and the workloads they support, offering improved query performance and reduced storage consumption. MongoDB automatically stores the collection\u2019s data in groups of related documents and indexes them based on their date values and unique group identifiers.<\/p>\n\n\n\n

In this article, I introduce you to the time series collection and demonstrate different ways you can create them in MongoDB Shell. If you want to try out the examples, you can use the version of Shell embedded in MongoDB Compass or the one you access through your system\u2019s command-line interface. You can also create time series collections in the Compass GUI, although this article focuses on the Shell commands.<\/p>\n\n\n\n

Note: For the examples in this article, I used the same MongoDB Atlas environment I used for the previous articles in this series. Refer to the first article for details about setting up these environments. For this article, the examples are based on the iot<\/code> database, which you can create in advance or when you try out the exercises.<\/p>\n\n\n\n

Adding a time series collection to a MongoDB database<\/h2>\n\n\n\n

To create a time series collection in MongoDB Shell, you can use the createCollection<\/code> method, just like you can for a conventional collection. The primary difference is that, for a time series collection, you must include the timeseries<\/code> option in your collection definition, as shown in the following syntax:<\/p>\n\n\n\n

db.createCollection(\n  \"collection_name\",\n  {\n    timeseries: \n    {\n      timeField: \"field_name\",\n      metaField: \"field_name\",\n      granularity_options\n    },\n    expireAfterSeconds: num_seconds\n  }\n);<\/pre>\n\n\n\n
The command\u2019s syntax consists of the following elements:<\/p>\n\n\n
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