CHECKPOINT
CHECKPOINT is a command in SQL Server that produces a stable state of the database at a certain point in time. It records all transactions that have been committed to the database to disk, reducing the work needed for recovery in case of failure. It functions as a mechanism to guarantee the consistency and integrity of the data in the database.
Example
CHECKPOINTOutput
Command(s) completed successfully.Explanation
The CHECKPOINT command is a transaction-SQL command which helps in reducing the time required for recovery in case of an unexpected shutdown or system failure. It creates a known good point from which the SQL Server Database Engine can start applying changes contained in the log during recovery after an unexpected shutdown or crash. However, there is no output returned from the SQL Server upon its execution except the message indicating the successful completion of the command.
Example
ALTER SYSTEM CHECKPOINT;Output
System altered.Explanation
The above ALTER SYSTEM CHECKPOINT; statement is used to enforce a database checkpoint in Oracle. In this case, the output “System altered.” confirms that the checkpoint operation has completed successfully. A checkpoint is a crucial part of the recovery mechanism in Oracle, ensuring data consistency by synchronizing the database and disk.