Introduction:

By default, a SQL Server database contains a primary data file and a transaction log file. However, it is a good practice to configure multiple data files and split data across them. Similarly, we can have multiple transaction log files for a database. SQL Server uses these log files in sequential order, but it does not provide any performance benefit. Ideally, it is recommended to have only one transaction log file per database.

Scenario:

Let’s assume we have a production database and we receive a critical alert that the disk is running out of space. After investigation, we find out that the disk holds a transaction log file that is full due to active transactions. We try shrinking the log file and backing up the transaction log, but it does not release the needed space. In this case, adding another transaction log file in a separate disk with free space can resolve the issue. However, we should remove the additional log file later to optimize performance.

Process of Removing Secondary Log File:

To remove the secondary transaction log file, we can use the ALTER DATABASE statement with the REMOVE FILE clause. However, we need to ensure that the secondary log file is empty before removing it. In a SQL database with a full recovery model, we can use transaction log backups to truncate the logs. Once the logs are truncated, we can safely remove the secondary log file.

Conclusion:

In this article, we explored the usage of multiple SQL Server transaction log files and the process of removing a secondary log file. It is important to avoid using multiple transaction log files, especially on production databases. It is recommended to take a database backup before performing any activity and to do it during non-productive hours.