Differential backup

[Akhi0587]

Dears, Do we have any scripts to calculate the size of differential backup? Let’s say full backup completed at 10:00am and want to take differential at 6:00pm, need to know the size of the differential before triggering the backup.

[olahallengren]

You can check it using the column modified_extent_page_count in sys.dm_db_file_space_usage.
https://docs.microsoft.com/en-us/sql/relational-databases/system-dynamic-management-views/sys-dm-db-file-space-usage-transact-sql