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

There is no "best" identity datatype. The various options have different strengths and weaknesses. I use GUIDs more often than not, but I have to deal regularly with disconnected clients and merge replication, so the choice is appropriate. If you don't have to deal with replication (i.e. the situation where a user adds new records while disconnected from the central database), an auto-incrementing int field is the better choice.