How about EOMONTH(InvoiceDate)?  Probably won't notice any performance issues with this - but if you do then revert to the DATEADD methods above.

I would only declare and set the start datetime - then calculate the end datetime.  With that said - do you want everything up to 1am but not including 1am? ...

SSIS has a function named TOKEN that is much easier to utilize than SUBSTRING and FINDSTRING.  It can also be utilized to break up the string based on multiple delimiters...

If this is a one-time process then why worry about 'automating' it as a parent/child package setup?  Put everything in a single package...

As for performance - have you...

One thing to take into consideration is that the first time you ran the test - the NOT IN actually loaded the buffer cache which is probably the majority of...

If you look at the logical reads for the following:

ActivityInstance
Schedule
ActivityType

They are much higher in database D - investigate why that is so different.

I cannot see the data in your file - but it doesn't look like EBCDIC encoded file, it looks like a standard ANSI file.  What happens if you set the...