You don't set query timeout in a stored procedure/TSQL. Query timeout is a client setting. You were on the right track w/ CommandTimeout.

It's not clear what you meant by "did...

Ideally, one plans for how valid they need/want the data to be vs. how much they're willing to pay to achieve that. e.g., if we must have valid addresses, then...

SQL Server does not use double pipes ("||") for concatenation --it uses the plus ("+") sign.

SQL Server 2012 introduced the CONCAT function as another alternative for concatenating strings.  One...

In the ATM case, the customer details you described belong to the customer's bank. As Scott described, the ATM transaction details are quite narrow. There are APIs/protocols that allow the...

It's not. Everything just inserted or updated is in the virtual "inserted" table, so the join adds no value.

Good observation.

It certainly can. It sounds like the update took a table lock on table_a to handle the big update.

No, a select doesn't insert, delete, or update data.

What is the error?

I'd guess it's related to not having aliased the subquery -- e.g.,

Declare @CopyFromUser Varchar(10) = (Select Top 1 * from
    ...

Be careful of leap years.

Using 365 days could give a different result than using 12 months or 1 year in a leap year  -- specifically on February 29th. Using month...

Is it id or wi_id?

In the select you are using

where wi_id = 123

But in the delete you are using

WHERE id = 123

As others have already mentioned, it is the SQL Server service account that needs permission to that folder.

Permissions aren't always inherited from the parent -- sometimes they get changed from...

Possibly.

Is sched_desc going to be the same for every row? Do you want a concatenated list or a single value?

You're using the SQL Server trick of concatenating multiple rows in...

Function in a select won't affect sargability. It would if it were being used in a where clause or join.

I doubt that you'd notice a difference in speed. Code would...

But for almost any RDBMS, it's probably a better idea to store the documents on a filesystem (or cloud storage), and store the paths and other necessary information in the...

Define "a large number"?

Are you creating/allowing user-specific schemas?

A schema is an object like a table. SQL is limited to 2,147,483,647 objects. As long as you are several orders of magnitude...