More DBA job interview questions and answers at
http://dba.fyicenter.com/Interview-Questions/
(Continued from previous question...)
What What does the term ACID refer to?
An acronym that describes concurrency support in a database
Explanation
The answer is an acronym that describes concurrency support in a database. ACID is an acronym for the following four terms:
* Atomicity - Every operation within a transaction is treated as a singular operation; either all of its data modifications are performed, or none of them is performed.
* Consistency - Once the transaction is completed, the system must be left in a consistent state.
* Isolation - It means that the operations within a transaction must be suitably isolated from other transactions. In other words, no other transactions should see data in the intermediate state, within the transaction, until it is finalized. This is done by using locks.
* Durability - Once a transaction is competed, all changes must be persisted as requested. The modifications should persist in total even in the event of a system failure.
(Continued on next question...)
