Section 15.7. ACID Compliance


15.7. ACID Compliance

The ACID (atomicity, consistency, isolation, and durability) model establishes four goals that every RDMBS must achieve if it wants to be ACID-compliant. A database that is not ACID-compliant will not be as reliable or resilient as an ACID-compliant database. Following are explanations of these four goals:


Atomicity

Changes to a database are "all or nothing." No matter what happens, a transaction is either a complete success or a complete failure.


Consistency

No transactions will be allowed that will place a database into an inconsistent state. If any transaction violates a given database's consistency rules, it will be rolled back.


Isolation

Transactions must not interfere with each other. For example, one transaction should not read intermediate data created by another transaction. This is primarily accomplished through logging.


Durability

Transactions committed to the database will not be lost for any reasons. This is what backups and transaction logs are for.




Backup & Recovery
Backup & Recovery: Inexpensive Backup Solutions for Open Systems
ISBN: 0596102461
EAN: 2147483647
Year: 2006
Pages: 237

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net