The common failure and recovery principle of database

system failure and Recovery principle

System failure is mainly due to the server in the running process, a sudden operating system errors, power outages and other causes of abnormal interruption, the user to the database processing of the transaction was suddenly interrupted, the memory buffer data are all lost, but hard disk, tape and other peripherals on the data has not been lost.

Dielectric failure and recovery principle

Media failure is due to physical damage to the storage media that occurs because of poor hardware reliability. All or part of the data in the database is lost and destructive.

Transaction failure and Recovery principle

A transaction failure is something that operates on a database that violates the conditions set by the system, such as input data errors, operational overflows, and so on, so that the transaction does not complete properly and terminates. In the event of a transaction failure, the transaction may have modified some of the data in the database operation, so the database management system must provide some kind of recovery mechanism to force rollback of all changes to the database by the transaction, bringing the system back to the state before the transaction occurred.