Adjacency List Pattern

Adjacency List Pattern Overview

At its core, adjacency list pattern 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 adjacency list pattern pays off across the whole codebase: fewer surprises, easier testing, and smoother onboarding. The snippet below is a solid starting point.

// single-table design: many entity types share one table
// USER#42 / PROFILE           -> user profile
// USER#42 / ORDER#2024-001    -> an order for that user
// ORDER#2024-001 / ITEM#1     -> a line item

const key = { pk: 'USER#42', sk: 'ORDER#2024-001' };

Single-table design models relationships through carefully composed partition and sort keys.

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

Amazon DynamoDB Cheatsheet

Handy DynamoDB (AWS SDK v3) reference related to adjacency list pattern.

How Adjacency List Pattern Works in DynamoDB

Adjacency List Pattern 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.

Single-table design models relationships through carefully composed partition and sort keys.

• 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 Adjacency List Pattern

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

Common Mistakes

• Skipping error handling and edge cases when wiring up adjacency list pattern.
• Leaving adjacency list pattern untested, so regressions slip into production.
• Over-engineering adjacency list pattern before you actually need the extra flexibility.
• Ignoring documentation, which makes adjacency list pattern hard for the next developer to change.

Key Takeaways

• Adjacency List Pattern is a core part of working effectively with DynamoDB.
• Start small and keep adjacency list pattern focused on a single responsibility.
• Apply consistent patterns so adjacency list pattern scales across your project.
• Test and document adjacency list pattern to keep it maintainable over time.