aws-dynamodb

aws-dynamodb Best Practices

This guide outlines the definitive best practices for interacting with AWS DynamoDB, ensuring optimal performance, security, and maintainability. We leverage AWS SDK v3, modern data modeling, and infrastructure-as-code principles.

1. Data Modeling: Single-Table Design is King

Embrace single-table design to minimize operational overhead and maximize query flexibility. Only use Global Secondary Indexes (GSIs) when your access patterns cannot be satisfied by the primary key.

✅ GOOD: Single-Table Design with Composite Primary Keys

Model your primary key (Partition Key + Sort Key) to serve your most frequent access patterns. Use generic attribute names like PK and SK to allow for diverse item types within the same table.

// Example: User and Order data in a single table
// PK: USER#<userId>, SK: #METADATA (for user details)
// PK: USER#<userId>, SK: ORDER#<orderId> (for user's orders)

interface UserItem {
  PK: string; // e.g., USER#123
  SK: string; // e.g., #METADATA
  userId: string;
  username: string;
  email: string;
}

interface OrderItem {
  PK: string; // e.g., USER#123
  SK: string; // e.g., ORDER#abc-123
  orderId: string;
  userId: string;
  orderDate: string;
  totalAmount: number;
}

// Access Pattern: Get User by userId -> Query: PK = 'USER#<userId>', SK = '#METADATA'
// Access Pattern: Get all Orders for a User -> Query: PK = 'USER#<userId>', SK begins_with 'ORDER#'

❌ BAD: Multi-Table Design for Related Entities

Creating separate tables for every entity type (e.g., UsersTable, OrdersTable) leads to increased operational complexity and often requires more complex cross-table queries or application-level joins.

// Don't do this unless absolutely necessary for strict isolation
// UsersTable: PK = userId
// OrdersTable: PK = orderId, GSI on userId

2. Code Organization and Structure

Organize your DynamoDB interactions into dedicated data access layers (DALs) or repositories. Use the AWS SDK v3's modular clients and async/await.