Question

A transaction updates a value A=10 to A=11. The transaction commits. There is a power failure, the system re-boots and comes back online. The value of A is 11 when users are back on the system.

Has the DBMS correctly followed the ACID properties, why or why not?

Answer 1

The updated value of A stored in non-volatile memory. Durability property is ensure that if the transaction commits but if any power failure or restarts occurs it should be durable enough to hold all its latest updates. it is often achieved through spearate transaction logs that can recreate all transactions like a backup.

Dbms followed the ACID properties becasue of the advantages of them when you are going to perfrom any logical opeeration with data. In simple words,First ,Atomicity-if the transaction was interrupted,your balace would remain unchanged. Seond one -Consistency, database must remain in consistent state after any transaction. Third, Durablity -Like above example if transaction commits or update,then database will hold the modified data, Fourth-isolation- multiple transactions can occur concurrently without leading inconsistency of database state.