SQL Interview: 109 Simple recovery and logging

This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around SQL Server and Azure SQL Database.

Section: Administration Level: Intro

Question:

You have a database configured for simple recovery model. You notice that the transaction log is still increasing in size.

What could cause this?

Answer:

Even in the Simple recovery model, it is quite normal to see the transaction log file grow. That does not necessarily mean it’s stuck or misconfigured.

In Simple recovery, the transaction log is automatically truncated after each checkpoint. This means the inactive log records (those no longer needed for recovery) are marked reusable.

However, truncation does not shrink the physical file — it just frees space inside it for reuse. So, the log file (.ldf) can still grow if the log has never grown large enough to handle your workload before, or if some process is temporarily preventing log truncation.

2026-01-12