Database Challenges

Here is the performance stats of the solution by dozauk for TSQL Challenge18.

--Simon_Mendoza_TSQLChallenge_18.sql
-- Standard 'Numbers Table' CTE
WITH   N3( n ) AS ( SELECT 1 UNION SELECT 0 )
,      N2( n ) AS ( SELECT 1 FROM N3 n1 CROSS JOIN N3 n2 )
,      N1( n ) AS ( SELECT 1 FROM N2 n1 CROSS JOIN N2 n2 )
,      N0( n ) AS ( SELECT 1 FROM N1 n1 CROSS JOIN N1 n2 )
,      Num AS ( SELECT n = ROW_NUMBER() OVER (ORDER BY n) FROM N0 ) 

-- Get first day of month and a unique ID for each requested month
,      Months AS    (SELECT Mth
                     ,     Yr