ACID PROPERTY OF TRANSACTION : TOPIC DBMS
Transaction Management
A sequence of many actions which are considered to be one atomic unit of work. A transaction is a collection of operations involving data items in a database. There are four important properties of transactions that a DBMS must ensure to maintain data in the face concurrent access and system failures.
Atomicity
Atomicity requires that each transaction is all or nothing. If one part of .the transaction fails, the entire transaction fails and the database state is left unchanged.
Consistency
If each transaction is consistent and the data base starts on as consistent, it ends up as consistent
Isolation
Execution of one transaction is isolated from that of another transactions. It ensures that concurrent execution of transaction results in a system state that would be obtained if transaction were executed serially, i.e., one after the other.
Durability
Durability means that once a transaction has been committed, it will remain even in the event of power loss, crashes, or errors. In a relational database, for instance, once a group of SQL statements execute, the results need to be stored permanently.
A sequence of many actions which are considered to be one atomic unit of work. A transaction is a collection of operations involving data items in a database. There are four important properties of transactions that a DBMS must ensure to maintain data in the face concurrent access and system failures.
Atomicity
Atomicity requires that each transaction is all or nothing. If one part of .the transaction fails, the entire transaction fails and the database state is left unchanged.
Consistency
If each transaction is consistent and the data base starts on as consistent, it ends up as consistent
Isolation
Execution of one transaction is isolated from that of another transactions. It ensures that concurrent execution of transaction results in a system state that would be obtained if transaction were executed serially, i.e., one after the other.
Durability
Durability means that once a transaction has been committed, it will remain even in the event of power loss, crashes, or errors. In a relational database, for instance, once a group of SQL statements execute, the results need to be stored permanently.
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