DynamoDB Global Tables

Global Tables Overview

At its core, global tables is about doing one thing well inside your DynamoDB project. Once you understand the pattern, you can apply it consistently across features and teams.

Good global tables pays off across the whole codebase: fewer surprises, easier testing, and smoother onboarding. The snippet below is a solid starting point.

import { DynamoDBClient } from '@aws-sdk/client-dynamodb';
import { DynamoDBDocumentClient, GetCommand, PutCommand } from '@aws-sdk/lib-dynamodb';

const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);

// reuse docClient across the module for efficient, typed access
await docClient.send(new PutCommand({ TableName: 'Orders', Item: { pk: '1' } }));

The DynamoDBDocumentClient maps plain JavaScript objects to DynamoDB item format for you.

Global Tables Example

import { DynamoDBClient } from '@aws-sdk/client-dynamodb';
import { DynamoDBDocumentClient } from '@aws-sdk/lib-dynamodb';

const docClient = DynamoDBDocumentClient.from(new DynamoDBClient({}));
// docClient.send(new PutCommand(...)) etc.

• Start from a minimal Global Tables example and grow it only as needed.
• Keep configuration explicit so Global Tables behaves the same in every environment.
• Name things clearly so teammates understand your Global Tables at a glance.
• Add tests around Global Tables early to lock in expected behaviour.

Amazon DynamoDB Cheatsheet

Handy DynamoDB (AWS SDK v3) reference related to global tables.

How Global Tables Works in DynamoDB

Global Tables builds on DynamoDB's key-value and document model, where every item lives in a partition chosen by its partition key and is optionally ordered by a sort key.

The DynamoDBDocumentClient maps plain JavaScript objects to DynamoDB item format for you.

• Design access patterns first, then model keys around them.
• Prefer Query over Scan for predictable performance.
• Use expressions to read and write only what you need.
• Keep items small and avoid hot partitions.

Practical Guidance for Global Tables

In production, global tables should be cost-aware and resilient. Right-size capacity, handle throttling with retries, and lean on indexes to support your query patterns.

Common Mistakes

• Copying global tables snippets without understanding what each line does.
• Skipping error handling and edge cases when wiring up global tables.
• Leaving global tables untested, so regressions slip into production.
• Over-engineering global tables before you actually need the extra flexibility.

Key Takeaways

• Global Tables is a core part of working effectively with DynamoDB.
• Start small and keep global tables focused on a single responsibility.
• Apply consistent patterns so global tables scales across your project.
• Test and document global tables to keep it maintainable over time.