Well, a simple google search would have turned up this link:

https://docs.microsoft.com/en-us/sql/sql-server/install/configure-the-windows-firewall-to-allow-sql-server-access?view=sql-server-2017

Are your log backups occurring every hour?  I would reduce that to 15 minutes.  By reducing the time between backups, they should decrease significantly in size, and subsequently applying them...

What settings did you choose when you ran the DMA?

That works.  But, you may see additional errors appear when running the app. The app may have something that tries to modify the database(s), such as shrinking(!) or something else.

That's...

Sounds like a firewall issue.  Are the firewall rules in place for all of the ports required for clustering, availability groups, etc?

One thing.  This is not a great design.

I would recommend trying to change the design on these tables.  Or, at minimum, create a regular extract of these tables into another...

Does this get you started?

 SELECT * 
  FROM test T
  CROSS APPLY DelimitedSplit8K(T.name, ';') NM
  CROSS APPLY DelimitedSplit8K(T.numbers, ';') NU 
  WHERE...

I think OP wants to make sure there won't be any incompatible code...

Unless I am missing something, you are only changing the compatibility level of the database?

Why won't this work?  What's the purpose of the DMA to simply change the compatibility level?

No, your WHERE clause is likely filtering the rows.

Without the actual SQL statement, and some sample data, that's an educated guess.

This is not unusual, unfortunately.

A lot of apps require sysadmin during install, so it can create the database, jobs, etc but usually it can be removed once installation is completed.

Are...

Hello! I have column in SQL 2012 DB of datatype smallint. Could you please let me know how to convert smallint to date? Here's the example of smallint data...

Just out of curiosity, I created semi-valid test of these three sets of code.  I took the code and inserted it into a regular table, and used the GO 111...

Hi there.  I am in agreement with the rest about adding a third node however I am guessing that your reason for suggesting this is down to cost which...

And 5 trips to the hardware store.