Is Guid the best identity datatype for Databases?

Question

It is connected to BI and merging of data from different data sources and would make that process more smooth.

And is there an optimal migration strategy from a data

Answer 1

Anything that can uniquely identify the record is a good identity data type. GUID is generally good, but it's not the optimum identity if you actually have a unique id coming from the source data. GUID is a random integer value that's guaranteed to be unique; however, in an integration situation, you often want to detect duplicates of information, not just match up the records.