update   dbo.MainTable
set     UNDERLYING_SYMBOL = STUFF(UNDERLYING_SYMBOL, 1, 1, '')
where    underlying_symbol LIKE '^%'

It's possible it would be far better to cluster the dbo.User_Events table by AuditTimestamp rather than UserID.  That could be a significant change, however, so if you would first run...

And to make the code not reliant on a particular DATEFIRST setting, don't use DATEPART, instead do this:

...
AND DATEDIFF(DAY, 0, a.date) % 7 <> 4 -- Ensure...

I need just the passenger events (0 or o,1).  But I think I may have gotten the answer from a colleague:

SELECT costCenterCode, scheduleDate, tripid, routeId, routename, activityId, eventOrder, CASE...

It's just another expression per value, not statement.  You could pre-code 10 or even 20 values without a lot of trouble:

SELECT ResourceType, CustomerID, DOB,
   ...

I'm not sure I fully understand the requirements.

Do you need the first and last [activityId] = 0 / IN (0, 1) in the partition regardless, or does some other row...

WITH cteRowNum(GroupName,AgentName,AgentEmail,

TicketsCompleted, RowNums) AS (

SELECT GroupName,AgentName,AgentEmail,TicketsCompleted,

DENSE_RANK() OVER(PARTITION BY GroupName ORDER BY TicketsCompleted DESC) AS RowNums

FROM Table

WHERE AgentName IS NOT NULL

)

SELECT cteRowNum.GroupName,cterowNum.AgentName,cteRowNum.AgentEmail, cteRowNum.TicketsCompleted

FROM cteRowNum

WHERE cteRowNum.RowNums = 1;

I assume you could have a Function2 and then data for it.  If so, there needs to be something to order the rows: an identity column, a datetime, etc..  Do...

Perhaps you could create a view with the columns in your (client's) preferred order?  It it was a full view, it should be updatable and therefore the view name could...

SELECT
    SUM(CASE WHEN HowManyDays <= 30 THEN thisAmt ELSE 0 END) AS aging_0_30,
    SUM(CASE WHEN HowManyDays >= 31 AND HowManyDays <=...

(1) Use differentials rather than full backups for most backups.  For example, daily diffs and only, say, weekly full backups.

(2) If you're not already using backup compression, and particularly if...

The value needs to be a string:

STRING_SPLIT('1008,1009,1011,1014',',')

A NULL value should not cause an error, ASCII(NULL) should just return NULL.

How do you define "week number"?  Are the first 7 days of the month "week 1", or is it based on specific day of the week?  For example, all weeks...

Increase the size of  your tempdb files.