Columnstore has its own quirks.  For example, every time you SELECT data from the table you'll read roughly 1M rows.  If your processing (almost) always does that anyway, such as...

I did give what I think is the reason for the recommendation: to be able to get back to the exact db image is something happens after removing TDE.

I get...

columnstore is an alternative to rowstore with page compression.

Typically you get even better compression with columnstore.

As to which is best, that depends on the specific situation with that table.

I'd say...

Do you really care that much?  That is, isn't it easier just to take the log backup.

I think I know the reason: it would be the only way to get...

ONLY if it's actually NEEDED, just because of the overhead to activate it.

I have (many) hundreds of dbs.  I have RCSI on for about a dozen or so of them. ...

When a page gets full, it is compressed(*), there does not have to be a rebuild first.

(*) SQL attempts to compress the page; if there's not enough gain from compression,...

In general, data compression is a huge performance gain.  Partitioning is not a particular performance if the table has its best possible clustering index, i.e. you lookup by the clus...

This statement:

ALTER DATABASE [MYDB] SET ALLOW_SNAPSHOT_ISOLATION ON

causes the db to start snapshot processing -- adding 14 bytes to each row and storing any needed row versions in tempdb -- and...

SELECT
    issuedate, replydate,
CASE WHEN replydate IS NULL AND DATEDIFF(DAY, duedate, GETDATE()) > 0 
         THEN DATEDIFF(DAY,...

DECLARE @date1 date
DECLARE @date2 date

SELECT ...
...
CROSS APPLY (
    SELECT dbo.fnGetSeconds(@date1) AS date1_secs,
    dbo.fnGetSeconds(@date2) AS date2_secs    
) AS alias1

...

My preferred approach is to use a CROSS APPLY to assign an alias name to the computation.  That name can then be used in any other clause in the SELECT,...

Should use the new file just fine.  Make sure the new file is present, or you will have no space to write to.

What's happening is this.  Your file has not...

Try SELECT too rather than PRINT, since SELECT can show more chars than PRINT.  Also, be sure to adjust the options in SSMS to show the max chars possible.

I

I have to...

Don't worry about ms, just use seconds.  A few ms diff could be caused by almost anything is and not significant for an SSIS package.