SQL Server database transaction log (explained)

Each time a change is written to a SQL Server database, the SQL Server database logs this change in its transaction log.

With the transaction log, you can roll back and undo changes to the SQL Server database through Microsoft® SQL Server Management Studio. By default, the SQL Server database stores its transaction log indefinitely which over time means that the transaction log has more and more entries. The transaction log is by default located on the system drive, and if the transaction log keeps growing, it may prevent Windows from running properly.

To avoid such a scenario, flushing the transaction log regularly is a good idea. Flushing it does not make the transaction log file smaller, but cleans its content and thereby prevents it from growing out of control. Your VMS system does not flush transaction logs. In SQL Server, there are ways of flushing the transaction log. Visit the Microsoft support page https://docs.microsoft.com/en-us/sql/relational-databases/logs/the-transaction-log-sql-server?view=sql-server-2017 and search for Transaction log truncation.