hashbytes
/* Checksum() isnt very good for detecting data changes. Use hashbytes() instead Example of output from script below: -361975519341300.801789 */ select avg(cast(cast(hsh as bigint) as decimal(25,0))) as truncatedHash from ( select cast(HASHBYTES('SHA1', [StringField1]+ [StringField2]+ [StringField3]) as binary(20)) as hsh FROM dbo.TableToBeInvestigated ) as hashedData