Understanding DBCC TEC

Ewald Cress explains (but does not document!) an undocumented DBCC command:

Boring old disclaimer: What I am describing here is undocumented, unsupported, likely to change between versions, and will probably make you go blind. In fact, the depth of detail exposed illustrates one reason why Microsoft would not want to document it: if end users of SQL Server found a way to start relying on this not changing, it would hamstring ongoing SQL Server improvement and refactoring.

With that out of the way, let’s dive right into DBCC TEC, a command which can dump a significant chunk of the object tree supporting a SQL Server session. This result is the same thing that shows up within a dump file, namely the output of the CSession::Dump() function – it’s just that you can invoke this through DBCC without taking a dump (cue staring match with Kendra). Until corrected, I shall imagine that TEC stands for Thread Execution Context.

I appreciate Ewald’s ability to make sense out of the madness of database internals.

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