Amazon DynamoDB provides support for transactions, allowing developers to perform multiple read and write operations across multiple items or tables atomically. DynamoDB transactions help maintain data integrity and consistency by ensuring that either all operations in the transaction succeed, or none of them do. Here's an overview of how DynamoDB handles transactions:
ACID Properties :* DynamoDB transactions adhere to the ACID (Atomicity, Consistency, Isolation, Durability) properties, ensuring that transactions are :
* Atomic : All operations in the transaction are treated as a single unit of work that either completes successfully or is rolled back entirely.
* Consistent : Transactions transition the database from one consistent state to another, preserving data integrity and enforcing constraints.
* Isolated : Transactions are isolated from concurrent transactions, ensuring that the effects of one transaction are not visible to other transactions until it is committed.
* Durable : Once a transaction is committed, its changes are durable and persistent, surviving system failures or crashes.
Transaction Scope :
* DynamoDB transactions can operate on multiple items within the same table, or across multiple tables within the same AWS account and region.
* Each transaction can include up to 25 unique items and a maximum of 4 MB of data.
* Transactions can involve a mix of read and write operations, including conditional writes and atomic counters.
Consistent Reads :
* DynamoDB transactions support strongly consistent reads, ensuring that all reads within the transaction reflect the most up-to-date data.
* Strongly consistent reads consume additional read capacity units (RCUs) compared to eventually consistent reads.
Isolation :
* DynamoDB transactions provide serializable isolation, the highest level of isolation, ensuring that transactions are executed as if they were the only transactions running in the system.
* Transactions are isolated from each other to prevent concurrency issues such as dirty reads, non-repeatable reads, and phantom reads.
API Support :
* DynamoDB offers transactional APIs for both the AWS SDKs and the AWS Command Line Interface (CLI).
* Developers can use transactional APIs to begin, commit, or abort transactions, as well as to execute read and write operations within transactions.
Use Cases :
* DynamoDB transactions are useful for a variety of use cases that require multi-item or multi-table updates with strong consistency and atomicity guarantees.
* Examples include financial applications, e-commerce systems, inventory management, and collaborative editing applications.
