Understanding Status In DMVs

Ewald Cress looks at a number of DMVs and how they expose query status:

sys.dm_exec_sessions: status

This metric is completely disjunct from the above ones, and mostly reflects attributes of a CSession class instance. The respective values are derived through the following decision tree:

  • If the internal Boolean member m_fIsConnReset is set, return dormant

  • Else if a flag living outside of CSession itself is set, return preconnect (I’ll touch on the source of this mystery flag below)

  • Else if a flag within the CSession itself is set (indicating that it has been provided some work to do) return running

  • Else return sleeping

It’s interesting to see how something so very similar can have so many different understandings.

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