DynamoDB Streams overview in AWS - Commands & Configuration

Introduction

Sometimes you want to know what changes happen to your database. DynamoDB Streams helps by recording these changes so you can react to them or keep track.

When you want to keep a log of all changes made to your DynamoDB table.

When you need to trigger other actions automatically after data changes, like sending notifications.

When you want to replicate data changes to another database or system.

When you want to audit who changed what and when in your database.

When you want to build real-time dashboards that update as data changes.

Commands

This command turns on DynamoDB Streams for the table named example-table. It records both the new and old versions of changed items.

Terminal

aws dynamodb update-table --table-name example-table --stream-specification StreamEnabled=true,StreamViewType=NEW_AND_OLD_IMAGES

Expected Output

{

    "TableDescription": {

        "TableName": "example-table",

        "StreamSpecification": {

            "StreamEnabled": true,

            "StreamViewType": "NEW_AND_OLD_IMAGES"

        }

    }

}

→

--stream-specification - Defines if streams are enabled and what data they capture

This command checks the current settings of example-table, including whether streams are enabled and their type.

Terminal

aws dynamodb describe-table --table-name example-table

Expected Output

{

    "Table": {

        "TableName": "example-table",

        "StreamSpecification": {

            "StreamEnabled": true,

            "StreamViewType": "NEW_AND_OLD_IMAGES"

        }

    }

}

This command lists the active streams for example-table so you can see the stream ARN to use in your applications.

Terminal

aws dynamodbstreams list-streams --table-name example-table

Expected Output

{

    "Streams": [

        {

            "StreamArn": "arn:aws:dynamodb:us-east-1:123456789012:table/example-table/stream/2024-06-01T12:00:00.000"

        }

    ]

}

Key Concept

If you remember nothing else from this pattern, remember: DynamoDB Streams records changes to your table so you can react to or track them.

Common Mistakes

Not enabling streams on the DynamoDB table before trying to read changes.

Without enabling streams, no change data is recorded and your application will not receive any events.

Always enable streams with the correct StreamViewType before expecting to consume stream data.

Choosing the wrong StreamViewType that does not include the data needed.

If you select KEYS_ONLY but need the full item data, you won't get the information you want.

Pick the StreamViewType (KEYS_ONLY, NEW_IMAGE, OLD_IMAGE, NEW_AND_OLD_IMAGES) that matches your use case.

Summary

Enable DynamoDB Streams on your table to start capturing changes.

Use the AWS CLI to verify stream settings and get the stream ARN.

Choose the right StreamViewType to capture the data you need.