ACIDvaatimusta

ACIDvaatimusta, also known as ACID properties, are a set of principles that guarantee reliable processing of database transactions. The acronym ACID stands for Atomicity, Consistency, Isolation, and Durability. These properties are crucial for maintaining the integrity and reliability of data in a database system.

Atomicity ensures that each transaction is treated as a single "unit," which either completes entirely or fails completely. If any part of the transaction fails, the entire transaction is rolled back to its initial state, preventing partial updates.

Consistency ensures that a transaction brings the database from one valid state to another, maintaining predefined rules such as constraints and cascades. This property guarantees that the database remains in a consistent state before and after the transaction.

Isolation ensures that concurrent transactions do not interfere with each other. Each transaction is executed as if it were the only one running, preventing issues such as dirty reads, non-repeatable reads, and phantom reads.

Durability ensures that once a transaction has been committed, it will remain so, even in the event of a system failure. This is typically achieved through logging and backup mechanisms that ensure the transaction's changes are permanently recorded.

ACID properties are essential for applications that require high reliability and data integrity, such as financial systems, e-commerce platforms, and healthcare applications. However, the strict adherence to ACID properties can sometimes lead to performance issues, particularly in high-concurrency environments. In such cases, alternative models like BASE (Basically Available, Soft state, Eventual consistency) are considered to balance performance and consistency.