ITGSS Certified Technology Specialist

In a Database Management System (DBMS), what function prevents conflicts due to simultaneous data access?

1. Data mirroring

2. Exclusive control

3. Cache invalidation

4. Data replication

The correct answer is: Exclusive control

In a Database Management System (DBMS), exclusive control plays a crucial role in preventing conflicts that can arise from simultaneous data access by multiple users or processes. This function ensures that when one user or application is accessing or modifying a piece of data, other users are prevented from doing the same until the first user has completed their operation. This is commonly addressed using mechanisms such as locks (either shared or exclusive), which coordinate access to data. By managing access in this way, exclusive control helps to maintain data integrity and consistency, avoiding issues such as lost updates and dirty reads. Understanding the other options amplifies the significance of exclusive control. Data mirroring refers to creating a duplicate of the database to improve availability or backup, but it doesn't manage concurrent access. Cache invalidation deals with making sure that cached data is updated or invalidated when the underlying data changes, which is also unrelated to controlling simultaneous access. Data replication involves copying data from one database to another for redundancy or load balancing, rather than managing how multiple accesses are synchronized. Thus, exclusive control is fundamentally the function that directly addresses the challenge of concurrent data access.