ACID

What does ACID mean?

ACID is an acronym that stands for Atomicity, Consistency, Isolation, and Durability. It is a Set of properties that are used to describe the behavior of database transactions. A transaction is a set of operations that are performed on a database as a single unit. If any of the operations in a transaction fail, the entire transaction is rolled back, and the database is restored to its state before the transaction began.

• Atomicity: Atomicity means that a transaction is either completed in its entirety or not at all. If any part of a transaction fails, the entire transaction is aborted and the database is restored to its original state.
• Consistency: Consistency means that a transaction must maintain the integrity of the database. This means that the transaction cannot leave the database in an inconsistent state. For example, a transaction cannot create a new record in a table without also creating a corresponding record in a related table.
• Isolation: Isolation means that a transaction must be independent of other transactions. This means that the results of a transaction cannot be affected by other transactions that are running concurrently.
• Durability: Durability means that a transaction must be permanent. Once a transaction has been committed, its effects are permanent and cannot be rolled back.

Applications

ACID properties are essential for ensuring the integrity and reliability of data in a database system. They are used in a wide Variety of applications, including:

• Online transaction processing (OLTP): OLTP systems are used to process large volumes of transactions in real time. ACID properties are essential for ensuring that these transactions are processed correctly and that the data in the database is always consistent.
• Data warehousing: Data warehouses are used to store and analyze large volumes of data. ACID properties are essential for ensuring that the data in a data warehouse is accurate and reliable.
• Business Intelligence: Business intelligence systems are used to analyze data and provide insights into business trends. ACID properties are essential for ensuring that the data used for business intelligence is accurate and reliable.

History

The concept of ACID was first proposed by Jim Gray in 1978. Gray was a computer scientist who worked on the development of database systems. He proposed ACID as a way to ensure the integrity and reliability of data in a database system.

ACID properties have been adopted by many database systems, including:

• MySQL
• PostgreSQL
• Oracle Database
• Microsoft SQL Server

ACID properties are an important part of database System Design. They ensure the integrity and reliability of data in a database system, which is essential for a wide variety of applications.