A database transaction is a performed within a database management system (DBMS) against a database, and it is often composed of one or more (usually in the form of SQL statements). The primary purpose of a transaction is to provide a reliable way to ensure data consistency and . Transactions are crucial in scenarios where multiple users or processes may concurrently access and modify the database to prevent data and ensure reliability.
A transaction begins with the "BEGIN TRANSACTION" statement. This indicates the start of a of work. SQL statements (e.g., , UPDATE, DELETE) are executed within the transaction to make changes to the database. After executing the SQL statements, the transaction can be either committed (if the changes are to be made permanent) or (if the changes need to be undone). The ACID approach is a set of properties that guarantee the reliability of database transactions. ACID stands for , Consistency, Isolation, and Durability.
Atomicity ensures that a transaction is treated as a , indivisible unit of work. If any part of the transaction fails, the entire transaction is rolled back, and the database is left unchanged. Consistency ensures that a transaction brings the database from one valid state to another. If a transaction violates any constraints, it is rolled back, maintaining the consistency of the database. Isolation ensures that the execution of one transaction is isolated from the execution of other transactions, preventing between transactions.
Keywords
rolled back | atomicity | integrity | interference | unit of work | single | integrity | unit | operations | corruption | insert |
