David Fowler shows how to use CHECKSUM and CHECKSUM_AGG to compare data:
There are times when we need to compare two tables and figure out if the data matches. I often see a number of ways of doing this suggested, most are quite slow and inefficient. I’d quite like to share a quick and slightly dirty way of doing this using the CHECKSUM and CHECKSUM_AGG functions.
CHECKSUM()
Just a reminder that CHECKSUM() will generate a checksum for an entire row or selection of columns in the row.CHECKSUM_AGG()
Will generate a checksum for a dataset.
David then has a couple of examples showing these in action.