Determine the need of concurrency control.

Concurrency control is essential in a database system for several reasons:

1. Data Consistency: Concurrency control ensures that a database remains consistent even when multiple users are accessing and modifying data simultaneously. Without concurrency control, the changes made by one user could interfere with the changes made by another, leading to inconsistent data.

2. Isolation: Concurrency control allows each transaction to operate as if it is the only one accessing the database. This isolation prevents the actions of one transaction from affecting the actions of another.

3. Deadlock Prevention: Concurrency control can help prevent deadlocks, situations where two or more transactions are each waiting for the other to release a resource. Deadlocks can cause a system to come to a standstill.

4. Atomicity: Concurrency control ensures that a transaction is treated as a single, indivisible operation. This means that either all of the changes in a transaction are made, or none of them are. This is important for maintaining data integrity.

5. Durability: Once a transaction has been committed, concurrency control ensures that the changes are permanent and will survive any subsequent system failures.

In summary, concurrency control is necessary to maintain the integrity, consistency, and reliability of a database system when multiple users are accessing and modifying data simultaneously.