This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: lock Types of Lock: Binary lock, Shared/Exclusive locks Although locks prevent serious data inconsistencies, they can lead to two major problems: The resulting transaction may not be serializable The schedule may create deadlocks. A database deadlock is caused when two transactions wait for each other to unlock data. Two-phase locking consists of: Growing phase, Shrinking phase The three basic techniques to control deadlocks are: Deadlock Prevention, Deadlock detection, deadlock avoidance Time stamps must have two properties: Uniqueness, Monotonicity When using time stamps to manage concurrent transactions, there are two schemes that can be applied to decide which transaction is rolled back and which continues executing: WAIT/DIE , WOUND WAIT SCHEMES Levels of Backup Full backup, differential backup, transaction log backup Concepts that affect the recovery process: Write-ahead-log-protocol, Redundant transaction logs, Database buffers, database checkpoints....
View Full Document
This note was uploaded on 08/30/2011 for the course COMPUTER computer taught by Professor Ms during the Spring '10 term at Oxford University.
- Spring '10