ACIDmodellen

ACIDmodellen refers to the guidelines for database management system transactions, ensuring data consistency and integrity in a multi-user environment. The term 'ACID' is an acronym for Atomicity, Consistency, Isolation, and Durability.

Atomicity refers to the concept that a database transaction must be treated as a single, indivisible unit of work. It must either complete in its entirety or have no effect at all, ensuring that a partial change is not made to the database.

Consistency is the property that each transaction must leave the database in a valid state. In other words, the database must remain in a consistent state after the transaction completes.

Isolation is the concept that multiple transactions must be able to execute concurrently without interfering with each other. This ensures that the outcome of a transaction does not depend on the order in which it is executed.

Durability is the characteristic that once a transaction has been committed, it must be preserved even in the event of a failure. This ensures that once a transaction has been completed, it cannot be rolled back, regardless of what happens to the database or the systems it relies on.

The ACID principles aim to ensure the reliability and correctness of database transactions by restricting how transactions are executed. They prevent the loss of data and ensure the consistency of data across multiple transactions, which is essential for maintaining data integrity.

ACIDmodellen are commonly used in commercial database management systems, including relational databases such as MySQL and PostgreSQL. They play a vital role in ensuring that database transactions are executed reliably and consistently, which is critical for maintaining data integrity and preventing losses due to errors or technical failures.