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How query LSN number in SQL Server?
Overview of SQL Server backups and LSN
- GO.
- declare @backupSetId as int.
- select @backupSetId = position from msdb..
- if @backupSetId is null begin raiserror(N’Verify failed.
- RESTORE VERIFYONLY FROM DISK = N’E:\DBbackup\SampleDB.bak’ WITH FILE = @backupSetId, NOUNLOAD, NOREWIND.
What is LSN number in SQL Server?
log sequence number
The log sequence number (LSN) value is a three-part, uniquely incrementing value. It is used for maintaining the sequence of the transaction log records in the database. This allows SQL Server to maintain the ACID properties and to perform appropriate recovery actions.
How is differential base LSN determined in SQL?
For a single-based differential backup; changes with LSNs greater than or equal to differential_base_lsn are included in the differential backup. For a multibased differential, the value is NULL, and the base LSN must be determined at the file level (see backupfile (Transact-SQL) ). For nondifferential backup types, the value is always NULL.
Which is an attribute of a differential database backup LSNS?
Some attributes of a differential database backup LSNs are: Some attributes of a transaction log backup LSNs are: The FirstLSN and CheckpointLSN of the first transaction log backup is also the first full database backup CheckpointLSN if the backup is taken when the database is idle and no replication is configured
When do LSN values change in SQL Server?
For the next full backup also, checkpoint_lsn and first_lsn values are the same but the database_backup_lsn value changes to first_lsn of the previous full backup Log backup after the full backup has the first_LSN value equals to last_lsn of the last log backup.
When does database _ backup _ LSN start in SQL?
Can be NULL. database_backup_lsn is the “begin of checkpoint” that is triggered when the backup starts. This LSN will coincide with first_lsn if the backup is taken when the database is idle and no replication is configured.