SQL Server has a number of settings set on a session that can influence the behaviour or queries. When debugging issues, it’s often useful to be able to get a list of all user sessions and their current settings to check nothing specific to the session is causing odd behaviour. The sys.dm_exec_sessions dynamic management view has a wealth of information on this. As well as containing all sorts of counters like CPU, Reads, Transaction counts etc is also lists all the settings that are set on each session.