Wednesday, December 19, 2012

What is ACID , in simple words


A stands for Atomicity, Atom is considered to be smallest particle which can not be broken into further
pieces.database transaction has to be atomic means either all steps of transaction completes or none of
them.
C stands for Consistency, transaction must leave database in consistent state even if it succeed or
rollback.
I is for Isolation
Two database transactions happening at same time should not affect each other and has consistent
view of database. This is achieved by using isolation levels in database.
D stands for Durability
Data has to be persisted successfully in database once transaction completed successfully and it has to
be saved from power outage or other threats. This is achieved by saving data related to transaction in
more than one places along with database.