Database Locking and Concurrency Control in Transaction Systems

Abstract

Database locking and concurrency control are important in transaction systems because multiple users and applications often access and modify the same data at the same time. These mechanisms help maintain data consistency, prevent conflicting updates, and ensure reliable transaction execution in enterprise database environments. Existing literature highlights shared locks, exclusive locks, row-level locking, table-level locking, optimistic concurrency control, pessimistic concurrency control, isolation levels, and deadlock handling as major techniques for managing concurrent transactions. However, many transaction systems still face challenges such as lock contention, deadlocks, lost updates, dirty reads, long waiting times, and reduced throughput during peak workloads. This research is important because weak concurrency control can affect transaction accuracy, application performance, financial records, inventory updates, and customer-facing operations. This article discusses database locking and concurrency control in transaction systems, focusing on lock types, transaction isolation, conflict detection, deadlock prevention, rollback handling, scheduling methods, and performance optimization. The study concludes that effective locking and concurrency control improve transaction reliability, protect data integrity, reduce conflicts, and support stable enterprise database performance.