Why concurrency control needed?

Concurrency control is needed in database management systems to ensure the correctness and consistency of data when multiple transactions occur simultaneously. Without proper control, issues such as lost updates, dirty reads, and inconsistent retrievals can arise, leading to data integrity problems. It helps manage the execution of transactions in a way that maintains isolation and durability, thus ensuring that the results are reliable and reflect the intended operations of all transactions. Overall, concurrency control is essential for maintaining data consistency in multi-user environments.