If my SQL 2014 instance was in 2012 compatibility mode, could the upgrade to SQL 2016 resulting in the DB upgrading to 2016 compatibility mode be causing the many...

And it doesn't matter which version of SSMS or SQL Server you're using.

Does partitioning by TENANTID improve query performance when most queries are filtered by tenant? For instance, will partitioning reduce the amount of data SQL Server scans, or is it...

Without saying it quite that way, that's been my whole...

Howdy and welcome aboard!

Please see the article at the first link in my signature line below for how to post "Readily Consumable Data" to help us give you the best...

Before I can give the demo I promised above, I need to know what the condition of the real table is.

In your example data, you have a DATE datatype column...

It would be real helpful it you listed the datatypes for the columns you are working with and pasted what the exact error message was.

Duplicate post.  Don't post here... post at the following link so we can keep any answers in one spot.

https://www.sqlservercentral.com/forums/topic/need-help-with-group-by-2

@ Bruin,

Which edition of 2016 do you have?  Standard or Enterprise?

It is possible that the patient entered the ER on a previous day. However, I'm focused on one day in order to work out that piece. I don't think...

I don't have a beef with the data provided.  I'd rather have "too much" than not enough.

I just need an answer to my previous question.  😀

Silly questions on my part because the likely answer is "Yes" to both of my questions but, I've got to make sure...

In your given example, is it possible that any...

Just to be sure, do you understand WHY it works?

People seem to be missing the point here.  The simple fact is that it...