Amazon DynamoDB is a fully managed, serverless, NoSQL database service provided by AWS. It is designed to handle large-scale applications that require fast, consistent, and low-latency performance for both reads and writes. DynamoDB is suitable for a variety of use cases, including web apps, mobile applications, gaming, IoT, and more.
DynamoDB is a key-value and document database that provides seamless scalability, strong consistency, and automatic multi-region replication. It supports both event-driven and transactional applications, with fully managed features to take care of operations like scaling, security, and availability.
Fully Managed:
DynamoDB is a serverless database service, meaning you do not have to manage infrastructure, servers, or scaling. AWS takes care of automatic scaling, patching, backups, and failover.
Scalable:
DynamoDB automatically scales to handle your application’s traffic, adjusting capacity up or down based on actual usage. It scales both read and write throughput independently, ensuring high availability and performance.
High Availability:
DynamoDB automatically replicates data across multiple Availability Zones (AZs) within a region, ensuring high availability and fault tolerance.
Performance:
It provides low-latency responses (in the single-digit millisecond range) even under high request volumes, making it ideal for real-time applications.
Fully Integrated with AWS Services:
DynamoDB integrates seamlessly with a range of AWS services such as AWS Lambda (for serverless applications), AWS Data Pipeline, Amazon Kinesis, Amazon Redshift, and Amazon CloudWatch for monitoring.
NoSQL Structure:
DynamoDB supports a flexible schema, allowing you to store data in key-value pairs or as documents (JSON-like format), offering scalability and flexibility for handling unstructured data.
Global Tables:
DynamoDB supports multi-region, fully replicated tables, allowing you to build globally distributed applications with low-latency access to data across multiple regions.
Encryption:
DynamoDB automatically encrypts data at rest using AWS KMS (Key Management Service) to protect your data.
Secondary Indexes:
DynamoDB allows the creation of global secondary indexes (GSI) and local secondary indexes (LSI), which improve query flexibility by allowing queries on attributes other than the primary key.
Transactions:
DynamoDB supports ACID transactions to provide a more robust database experience, enabling atomicity, consistency, isolation, and durability for multi-item and multi-table operations.
Event-Driven Architecture:
With DynamoDB Streams, you can capture and store changes to your DynamoDB table, and use AWS Lambda to trigger functions based on changes to the data (for real-time data processing).
DynamoDB TTL (Time to Live)
is a feature that allows you to define a timestamp on items in your DynamoDB table, after which those items will be automatically deleted. This feature is designed to help reduce storage costs and manage data lifecycle efficiently without the need for manual intervention.
Data Model
DynamoDB uses a key-value store and document model that consists of the following key components:
Tables:
The basic unit of storage. Each table has a primary key and can contain multiple items (records).
Primary Key:
The primary key uniquely identifies each item in the table. There are two types:
Partition key (hash key): A single attribute that uniquely identifies each item.
Composite primary key: Combines a partition key and a sort key for more complex queries.
Attributes:
The individual data elements within an item (e.g., attributes like name, address, etc.).
Items:
The individual records or rows in the table.
Indexes:
Global Secondary Indexes (GSI): Allow queries on non-primary key attributes, with the ability to project specific attributes.
Local Secondary Indexes (LSI): Allow queries based on a non-primary key attribute, but with the same partition key as the base table.