What is the fastest way to populate a new column with character values?
Hi, I have a script that does an advanced table concatenation, and I want to add 'source columns' to indicate the original table names. I have a few methods that work but all are slow for large tables. I also tried a formula method but it wasn't quick either. Is there some other trick I can use?Example below very closely matches what I'm doing. Data table sizes of 1M rows are not unusual, so I'd r...