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Comparing Data With CHECKSUM

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.

Just a reminder that CHECKSUM() will generate a checksum for an entire row or selection of columns in the row.

Will generate a checksum for a dataset.

David then has a couple of examples showing these in action.