DynamoDB Streams and Global Tables
Learn how to react to data changes in real time with DynamoDB Streams and build multi-region, low-latency applications using Global Tables.
DynamoDB Streams and Global Tables is a free AWS for Backend Developers (EC2, S3, RDS, Lambda) lesson on CoddyKit — lesson 4 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the AWS for Backend Developers (EC2, S3, RDS, Lambda) learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Reacting to Changes
Sometimes you need to know the moment data changes — to update a cache, send a notification, or sync another system.
DynamoDB Streams capture an ordered log of every item-level change in a table.
What a Stream Records
Each stream record describes an INSERT, MODIFY, or REMOVE. You choose what data the record carries via the stream view type:
- KEYS_ONLY
- NEW_IMAGE
- OLD_IMAGE
- NEW_AND_OLD_IMAGES
Enabling a Stream
Enable a stream on a table and pick a view type.
aws dynamodb update-table \
--table-name Orders \
--stream-specification StreamEnabled=true,StreamViewType=NEW_AND_OLD_IMAGESStreams Trigger Lambda
The most common pattern is connecting a stream to a Lambda function. Lambda is invoked in batches as records arrive, letting you process changes serverlessly.
exports.handler = async (event) => {
for (const record of event.Records) {
console.log(record.eventName, record.dynamodb.Keys);
}
};Common Stream Use Cases
Streams power many patterns:
- Keeping a search index (OpenSearch) in sync
- Aggregating analytics
- Sending notifications on changes
- Replicating to another data store
Ordering and Shards
Streams are organized into shards. Records within a shard are strictly ordered by the sequence in which changes occurred, which preserves per-item change order.
Introducing Global Tables
Global Tables replicate your DynamoDB table across multiple AWS regions automatically, giving users low-latency access no matter where they are.
Multi-Region, Active-Active
Global Tables are active-active: you can read and write in any region, and changes replicate to the others, typically within a second.
Global Tables are built on top of DynamoDB Streams under the hood.
Conflict Resolution
When the same item is written in two regions at once, DynamoDB resolves the conflict using a last writer wins strategy based on timestamps.
When to Use Global Tables
Reach for Global Tables when you need:
- Low latency for a worldwide user base
- Regional disaster recovery
- Multi-region active-active applications
Streams vs Global Tables
Remember the distinction:
- Streams — react to changes within your own systems
- Global Tables — replicate the table itself across regions
Global Tables use Streams internally to do their work.
Quick Check
Test your DynamoDB knowledge.
Recap
You learned advanced DynamoDB features:
- Streams capture ordered item-level changes
- Streams commonly trigger Lambda
- Global Tables replicate active-active across regions
- Conflicts resolve with last writer wins
Together they enable real-time, globally distributed applications.
Frequently asked questions
Is the “DynamoDB Streams and Global Tables” lesson free?
Yes — the full text of “DynamoDB Streams and Global Tables” is free to read here on the web, and the AWS for Backend Developers (EC2, S3, RDS, Lambda) course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the AWS for Backend Developers (EC2, S3, RDS, Lambda) course, upgrade to CoddyKit PRO.
What will I learn in “DynamoDB Streams and Global Tables”?
Learn how to react to data changes in real time with DynamoDB Streams and build multi-region, low-latency applications using Global Tables. You practise AWS for Backend Developers (EC2, S3, RDS, Lambda) with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start AWS for Backend Developers (EC2, S3, RDS, Lambda)?
No prior experience is required. AWS for Backend Developers (EC2, S3, RDS, Lambda) on CoddyKit is structured for beginners through advanced learners; this is — lesson 4 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “DynamoDB Streams and Global Tables” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this AWS for Backend Developers (EC2, S3, RDS, Lambda) lesson?
Yes. Every AWS for Backend Developers (EC2, S3, RDS, Lambda) lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- RDS Read Replicas and Multi-AZ
- Introduction to DynamoDB
- DynamoDB Data Modeling
- DynamoDB Streams and Global Tables