So, I have two different databases:
1st database includes timestamps in the following format:
Purchase_date
12.Nov. 2009
13.Nov.2009
19.Nov.2009
2nd database includes timestamps in the same format:
HeaderStartDate
13.Nov2009
24.Nov.2009
Both, have a common identifier column which is a serial number.
I want to check if headerStartDate is included in the column Purchase_date if not to ADD IT to the Purchase date.
I tried to Join the two databased based on the serial number but because are huge (80million*3) it loads forever.
Could you please advice me how to solve my issue? any clever idea?