SQL Interview: 108 Increasing memory consumption

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: Medium

Question:

You are reviewing the memory usage of a Windows Server running SQL Server. It appears to have almost run out of memory.

You add additional memory, and monitor the usage of the memory by SQL Server. It appears to always be constantly increasing, until the server is almost out of memory again.

Is it likely that the instance of SQL Server has a memory leak?

Answer:

Probably not. What you’re seeing is normal SQL Server behavior.

SQL Server is designed to use all the memory you’ll let it, as a cache (buffer pool, plan cache, columnstore/object pool, etc.). After you add RAM, the process will steadily grow toward its target and hold onto it to keep reads fast. That can look like a leak, but it’s by design — SQL Server will release memory under OS pressure (and even faster if you’ve set a sensible cap).

A steadily increasing SQL Server working set is almost always normal cache growth, not a memory leak. Set an appropriate max server memory cap and monitor; if Total tracks Target and the server remains responsive, there is no issue that needs attention.

2026-01-10