You're retiring? :unsure:

SELECT -- flatten to one row...

Very unusual plan - so many rows from both sides, yet it's a nested loops join and then a key lookup too. I wonder how it would fare with a...

With those three minor data corrections, this query appears to work:

;WITH Headers AS ( -- 18 rows
 SELECT *
 FROM #MST_SESSION_TEST p
 CROSS APPLY (

Hey Johan, the plain query shows an optimiser timeout - odd, because it's quicker than the plan which doesn't timeout. Here are a couple of variants of your CTE version,...

"American-style IPA" doesn't have to be awful. Here's probably the best IPA in the world: http://www.thornbridgebrewery.co.uk/product.php?s=jaipur
Reading is a desert when it comes to decent food but...