Category : Java
| Sub Category : Interview Questions | By Prasad Bonam Last updated: 2023-07-17 14:18:17
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ACID is an acronym that stands for Atomicity, Consistency, Isolation, and Durability. These properties are fundamental to transaction processing in databases and ensure reliable and consistent data operations. Lets explore each of the ACID properties:
Atomicity: Atomicity refers to the "all-or-nothing" property of a transaction. It ensures that a transaction is treated as a single, indivisible unit of work. Either all the changes made by the transaction are committed to the database, or none of them are. If any part of the transaction fails, the entire transaction is rolled back, and the database remains unchanged.
Consistency: Consistency ensures that a transaction brings the database from one consistent state to another. It means that the data in the database must adhere to defined integrity constraints, domain constraints, and validation rules. If a transaction violates any of these constraints, it is rolled back, and the database remains unchanged.
Isolation: Isolation ensures that concurrent transactions do not interfere with each other. Each transaction is isolated from others, giving the impression that it is executed in isolation, independently of other transactions. Isolation prevents problems such as dirty reads, non-repeatable reads, and phantom reads. It ensures that the data accessed by one transaction is consistent and unaffected by other concurrent transactions.
Durability: Durability guarantees that once a transaction is committed, its changes are permanent and will survive any subsequent system failures, such as power outages or crashes. Committed data is stored in a way that it can be recovered, even in the event of a system failure. This is usually achieved by persistently writing transaction changes to disk or other non-volatile storage.
These ACID properties collectively ensure that database transactions are reliable, consistent, and maintain data integrity. They provide a strong foundation for maintaining data consistency, even in the presence of concurrent transactions and system failures. ACID compliance is crucial in applications where data integrity and reliability are of paramount importance, such as financial systems, e-commerce platforms, and critical business operations.