SQL Server database full backup not only backup data but also logs

I used to think that the full backup of SQL Server only backs up the data in the database and does not contain logs. In fact, this is an error. Using RESTOREHEADERONLY can help us verify (msdb. dbo. backupset also contains the relevant information ).

Restore headeronly returns the result set that contains all the backup headers of all backup sets on a specific backup device. The query result contains three columns:

FirstLSN	Numeric (25, 0)	The log serial number of the first log record in the backup set.	NULL
LastLSN	Numeric (25, 0)	The log serial number of the next log record after the backup set.	NULL
CheckpointLSN	Numeric (25, 0)	Log number of the last checkpoint when the backup is created.	NULL

The database starts to read data after the CHECKPOINT. Some PAGE data may have been changed during data reading, but the SQL SERVER does not read the data again. In this way, the LSN of the changed PAGE needs to be included, in this way, the log operation is re-applied to the database (REDO/UNDO) during restoration ).

RESTOREHEADERONLY (Transact-SQL): http://technet.microsoft.com/zh-cn/library/ms178536 (v = SQL .90). aspx