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Flashcards in 3: Recovery Deck (6)
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What is recovery and what is it used for ?

Used in an event of failure that may leave the DB in an inconsistent state.


When may a failure occur?

At any point, including the period when data held in buffers is being written to disk for permanent storage.


How is a transaction log used ?

The recovery manager establishes the status of any update operations performed by a transaction that may be affected by failure in the system.


Name the two types of recovery technique ?

- Deferred Recovery

- Immediate Recovery


Which technique favours applying updates to the database (i.e. ‘to disk’, ‘to secondary storage’) when the write operation is performed?

Immediate Recovery


Which technique employs ‘force-writing’ of the log to disk in order to preserve the Before-Image (i.e. the old values of the database)?

Immediate Recovery