This article presents a utility that will show you what SQL statements are using the transaction logs, in terms of log space used and transaction duration.
Tony Davis answers 10 surprisingly tricky questions about SQL Server Transaction Log.
As a DBA, it is vital to manage transaction log growth explicitly, rather than let SQL Server auto-growth events "manage" it for you. If you undersize the log, and then let SQL Server auto-grow it in small increments, you'll end up with a very fragmented log. This article demonstrates how this can have a significant impact on the performance of any SQL Server operations that need to read the log.
Kun Lee had a database where the log file kept growing and used 99.99% of the available space. He noticed miscellaneous change data capture objects still in the database as well as open transactions. This was causing his transaction log to continue to grow, but he couldn't disable CDC, because SQL Server thought it was not enabled. Read the full article to see his solution.
When a SQL Server database is operating smoothly and performing well, there is no need to be particularly aware of the transaction log, beyond ensuring that every database has an appropriate backup regime and restore plan in place. When things go wrong, however, a DBA's reputation depends on a deeper understanding of the transaction log, both what it does, and how it works.