Why might unmanaged memory account for over 60% of memory used by console application?-Collection of common programming errors

You will inevitable use unmanaged code when accessing a database. The interface to the engine is always code that’s been around for a long time, predating .NET and wrapped by managed classes that provide the interop. True for, say, SQL Server and any provider that piggy-backs onto OleDb or ODBC.

These managed classes will always implement IDisposable so you can release the resources consumed by the native provider early. Forgetting to do so is very common and rarely noticed. Other than seeing the process running “heavy”, seemingly consuming a lot of handles and unmanaged memory for no good reason. This will be especially the case when the garbage collector does not run frequently enough, something you can see with Perfmon.exe. So beyond not using Dispose, part of the problem can be that you don’t do enough work with these DTO objects yet to get enough GC churn.

Review your code and ensure you use Dispose() and the using statement where required.