Amazon DocumentDB vs Amazon DynamoDB: What are the differences?

Introduction

Amazon DocumentDB and Amazon DynamoDB are two popular database services offered by Amazon Web Services (AWS). While both are designed to store and manage data, they have some key differences that set them apart.

1. Database Structure: Amazon DocumentDB is a document-oriented NoSQL database that uses a JSON-like format to store and retrieve data. It allows for flexible and scalable schema design and supports complex queries. On the other hand, Amazon DynamoDB is a key-value store NoSQL database that stores data in tables and uses primary keys for data retrieval. It is highly scalable and can handle millions of requests per second.

2. Data Consistency Model: Amazon DocumentDB provides immediate, read-after-write consistent data, ensuring that any read operations after a write operation will always return the updated data. In contrast, Amazon DynamoDB by default provides eventual consistency, which means that there may be a slight delay in getting the most up-to-date data after a write operation. However, DynamoDB also offers strong consistency as an option.

3. Scaling Capabilities: Amazon DocumentDB allows horizontal scaling by adding additional instances to a cluster. This enables high availability and increased capacity as the workload grows. On the other hand, Amazon DynamoDB scales automatically and does not require manual intervention for handling increased traffic or storage needs. It can seamlessly handle bursts of traffic without impacting performance.

4. Supported Workload: Amazon DocumentDB is well-suited for applications that require complex queries, extensive data modeling, and real-time analytics. It is a good choice for scenarios where data structures evolve over time and flexibility in schema design is important. On the contrary, Amazon DynamoDB is geared towards applications that require high throughput and low latency for large volumes of read and write operations. It excels in scenarios such as gaming leaderboards, session management, and real-time streaming data.

5. Pricing Model: Amazon DocumentDB is priced based on the instance size and the storage capacity used, with separate charges for additional data transfer. On the other hand, Amazon DynamoDB is priced based on the provisioned read and write capacity, with additional charges for storage and data transfer. DynamoDB offers on-demand pricing as well for applications with unpredictable workloads.

6. Geographical Distribution: Amazon DocumentDB can be provisioned in multiple Availability Zones within an AWS region for improved fault tolerance and low-latency data access. Amazon DynamoDB is a fully managed, multi-region and multi-master database service that can be globally distributed with automatic replication of data across regions for high availability.

In Summary, Amazon DocumentDB is a document-oriented NoSQL database with flexible schema design and immediate consistency, suitable for complex queries and analytics. Amazon DynamoDB is a key-value store NoSQL database with high scalability and low latency, ideal for applications with high throughput and low latency requirements.