How to Enable Streams in DynamoDB: Step-by-Step Guide

To enable DynamoDB Streams, update your table settings to activate the stream and choose the stream view type like NEW_IMAGE or NEW_AND_OLD_IMAGES. You can do this via the AWS Management Console, AWS CLI, or SDK by specifying the StreamSpecification when creating or updating the table.

Syntax

To enable streams on a DynamoDB table, you specify the StreamSpecification parameter with two parts:

• StreamEnabled: Set to true to turn on streams.
• StreamViewType: Defines what data the stream captures, such as NEW_IMAGE (new item state), OLD_IMAGE (old item state), NEW_AND_OLD_IMAGES, or KEYS_ONLY.

json

StreamSpecification={
  StreamEnabled: true,
  StreamViewType: 'NEW_IMAGE'  
}

Example

This example shows how to enable streams on an existing DynamoDB table using AWS CLI and AWS SDK for JavaScript (v3). It sets the stream to capture the new image of items.

bash and javascript

## Using AWS CLI to enable streams on a table named 'MyTable'
aws dynamodb update-table \
  --table-name MyTable \
  --stream-specification StreamEnabled=true,StreamViewType=NEW_IMAGE

// Using AWS SDK for JavaScript v3
import { DynamoDBClient, UpdateTableCommand } from "@aws-sdk/client-dynamodb";

const client = new DynamoDBClient({ region: "us-east-1" });

async function enableStream() {
  const params = {
    TableName: "MyTable",
    StreamSpecification: {
      StreamEnabled: true,
      StreamViewType: "NEW_IMAGE"
    }
  };

  try {
    const data = await client.send(new UpdateTableCommand(params));
    console.log("Stream enabled:", data.TableDescription.StreamSpecification);
  } catch (err) {
    console.error(err);
  }
}

enableStream();

Output

Stream enabled: { StreamEnabled: true, StreamViewType: 'NEW_IMAGE' }

Common Pitfalls

Common mistakes when enabling streams include:

• Not specifying StreamViewType, which is required when enabling streams.
• Trying to enable streams on a table that already has streams enabled with a different view type without updating properly.
• Forgetting to update IAM permissions to allow reading from streams.

json

## Wrong: Missing StreamViewType
StreamSpecification={
  StreamEnabled: true
}

## Right: Include StreamViewType
StreamSpecification={
  StreamEnabled: true,
  StreamViewType: 'NEW_IMAGE'
}

Quick Reference

Parameter	Description	Example Values
StreamEnabled	Enable or disable streams	true, false
StreamViewType	Type of data captured by stream	KEYS_ONLY, NEW_IMAGE, OLD_IMAGE, NEW_AND_OLD_IMAGES

Key Takeaways

Enable streams by setting StreamEnabled to true and specifying StreamViewType.

Choose the StreamViewType based on what item data you want to capture in the stream.

Use AWS CLI, SDK, or Console to enable streams on existing or new tables.

Always update IAM permissions to allow access to DynamoDB streams.

Remember to specify StreamViewType; it is required when enabling streams.