In SQL Server, what does the transaction log include?

In SQL Server, what does the transaction log include?

• The after-image of a record
• The before and after-image of a record
• The essential data of the record
• The before-image of a record 

EXPLANATION

The simple answer is that a data backup must include some transaction log otherwise the backup isn’t valid. When a database backup is restored, the result must be a transactionally consistent database (i.e. with no uncommitted transactions or structural inconsistencies).

Every SQL Server database has a transaction log that records all transactions and the database modifications made by each transaction.
The transaction log is a critical component of the database. If there is a system failure, you will need that log to bring your database back to a consistent state.