CODEWITHSUNDEEP
databaseoracle-databasedata-recovery
Henok Tesfaye
Henok Tesfaye

Reputation: 9580

How does DBMS utilize undo buffer and redo log files to recover changes made to the database?

How does DBMS utilize undo buffer and redo log files to recover changes made to the database?

Upvotes: 2

Views: 445

Answers (1)

Biruk Misanaw
Biruk Misanaw

Reputation: 141

For example on Oracle, Redo log files record changes to the database as a result of transactions and internal Oracle server actions. And this files protect the database from the loss of integrity because of system failures caused by power outages, disk failures, and so on. Undo, on the other hand, is stored in the buffer cache which can be on the form of undo table-space. Undo table-spaces are special table-spaces used solely for storing undo information. Each database contains zero or more undo table-spaces. Undo records are used to Roll back transactions when a ROLLBACK statement is issued and Recover the database.

source: https://oraclenz.wordpress.com/2008/06/22/differences-between-undo-and-redo/

Upvotes: 2

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