Let's just look at TableOne, TableTwo, and TableFour
Most of the condition in the "in where" in are already covered in the join
And suggest you use join on for all
Select TableTwo.Column1, DatabaseTwo..
from TableOne
inner join TableTwo on TableOne.Column4 = TableTwo.Column4
inner join TableFour on TableOne.Column6 = TableFour.Column6
where 1 = 1
--- Section 2
and TableOne.Column6 in (Select TableOne.Column6
from TableOne, TableTwo, TableFour
Where TableOne.Column4 = TableTwo.Column4 -- covered in base join
and TableOne.Column6 = TableFour.Column6 -- covered in base join
and TableFour.Column16 >= @StartDate
and TableFour.Column16 < @EndDate )
Pretty sure this is the same query
Not sure if it is faster but I doubt is is slower
The query optimizer has a better chance of filtering early
Select TableTwo.Column1, DatabaseTwo..
from TableOne
inner join TableTwo on TableOne.Column4 = TableTwo.Column4
inner join TableFour on TableOne.Column6 = TableFour.Column6
and TableFour.Column16 >= @StartDate
and TableFour.Column16 < @EndDate