You know why it's called Crystal right? ...

As a former DBA and now Data Architect, the way I view this is that while the developers are writing the queries and code, the DBA should guide them in...

Is there an index on AccountID and Date columns of dbo.BalanceTable?

Those conditions are in all your UPDATE statements, but the only index you've shown us is the Primary Key on...

...I think the potential irony of the whole mess is that fewer people are flying, so the airlines aren't making as much money. After the fighting in both directions...

This script will find users in a database that don't have an exact match for login based on SID, but I think it overstates the number of orphans because if...

What context was NOT IN being used, with a list of values or with a subquery?  Depending on the code you are looking at, maybe the NOT IN could be...

It seems fairly straightforward, what part are you  having problems with?  If you're not sure what some of the datemath is doing, try some of it outside of this script...

A simple but free tool is ApexSQL Model:

https://www.apexsql.com/sql-tools-model.aspx

I've used it here and there before, it can do reverse engineering of a model from an existing database, as well as...

If you just want to reload one table instead of the entire database, I...

Microsoft introduced the new Cardinality Estimator in the SQL Server engine in 2014.  If the database was set to an older compatibility mode, it was still using the old cardinality...

Also is there a connection between CPU pressure and Memory , say I notice constant High CPU- 90% on a sql server instance, and cannot add more CPU's will...

Are there a lot of OS level page swaps happening?  If not there may not be any problems.  Here's an article about monitoring that:

https://docs.microsoft.com/en-us/azure/monitoring/infrastructure-health/vmhealth-windows/winserver-memory-pagespersec

Typically you want most of your...

I think it might be tied to the Deployment Target Version.  In the menu, select Project / Properties.  Check the TargetServerVersion property, that relates to the script language used.

If a deadlock occurs, a rollback happens like Mike says.  If it is still rolling back, you won't be able to kill the rollback, you will just have to wait...

I agree with other people's comments on encapsulation and security.  Here are my additional comments on why I believe it's better to use stored procedures than code queries directly within...