What action occurs with each commit to ensure changes are recorded?

What action occurs with each commit to ensure changes are recorded?

• A. A savepoint is executed every time
• B. A snapshot is created for recovery
• C. A write to the transaction log occurs
• D. A backup is initiated

Answer: (C)

The correct answer highlights a fundamental mechanism in database management systems, specifically regarding how transactions are handled and ensured for data integrity. Each time a commit is executed, a write to the transaction log occurs. This action is essential because the transaction log is a crucial component that records all changes made to the database during a transaction. When a transaction is committed, the system records the details of that transaction in the log, which allows the database to maintain a history of all operations performed. This is vital for recovering the database in case of a failure, as the log can be used to redo or undo transactions. Writing to the transaction log not only helps maintain data integrity but also supports features like point-in-time recovery and replication. The other options involve processes related to data management but do not occur specifically with each commit. For instance, executing a savepoint allows for marking points within a transaction that can be rolled back to, but this is not automatically done with every commit. A snapshot for recovery represents a saved state of the database at a point in time, but this is not directly tied to the commit action. Similarly, initiating a backup is a separate process that can be scheduled independently of transaction commits and is not triggered every time a commit occurs. Thus, the

The correct answer highlights a fundamental mechanism in database management systems, specifically regarding how transactions are handled and ensured for data integrity. Each time a commit is executed, a write to the transaction log occurs. This action is essential because the transaction log is a crucial component that records all changes made to the database during a transaction.

When a transaction is committed, the system records the details of that transaction in the log, which allows the database to maintain a history of all operations performed. This is vital for recovering the database in case of a failure, as the log can be used to redo or undo transactions. Writing to the transaction log not only helps maintain data integrity but also supports features like point-in-time recovery and replication.

The other options involve processes related to data management but do not occur specifically with each commit. For instance, executing a savepoint allows for marking points within a transaction that can be rolled back to, but this is not automatically done with every commit. A snapshot for recovery represents a saved state of the database at a point in time, but this is not directly tied to the commit action. Similarly, initiating a backup is a separate process that can be scheduled independently of transaction commits and is not triggered every time a commit occurs. Thus, the