600M records is a LOT of records. Even if your disc speed (both read and write) is great, upi have loads of RAM, etc, it is going to take a...

My knowledge of C# is pretty low (I can read it, but not write it), however, maybe try some cell formatting. A Google brought me to this conclusion, however, this...

You haven't named your column. For example:
SELECT CAST(Start_Date AS date) AS Start_Date
FROM Table
WHERE Start_Date > GETDATE();

Not a great fan of looping through the parameters.

It's also worth noting that if you have a subscription running, and try to run it again (at least with...

I've assumed that you will likely want to parametrise this. Without DDL and DLM, this is completely untested, however:
DECLARE @DateFrom date, @DateTo date;
SET @DateFrom = '20171030';

Nevermind

Considering you're doing a COUNT, why not instead do:
COUNT(CASE InspectionClosed WHEN '1900-01-01 00:00:00.000' THEN NULL ELSE InspectionClosed END)
NULLs are not counted when using the aggragate, so making those values...

This really isn't SQL related (well it isn't at all apart from my attempt to get multiple SQL instances running on a single Linux Machine), but anyone got any experience...