ACID proerties in SQL Server
every database should ensure these 4 properties called ACID. ACID stands for
A - Atomicity
C - Consistency
I - Isolation
D - Durability
a transaction to transfer funds from one account to another involves making a,
withdrawal operation from the first account and a deposit operation on the second.
If the deposit operation failed, you don’t want the withdrawal operation to happen either.
a database tracking a checking account may only allow unique check numbers to exist for each transaction
a teller looking up a balance must be isolated from a concurrent transaction involving a withdrawal from the same account.
Only when the withdrawal transaction commits successfully and
the teller looks at the balance again will the new balance be reported.
A system crash or any other failure must not be allowed to lose the results of a transaction
or the contents of the database. Durability is often achieved through
separate transaction logs that can “re-create” all transactions from some picked point in time (like a backup).