Hash 128 uniqueness

[AbdullahMastan]

Greetings, 

Does Hash128 create the same hash for duplicate values present in the field its applied upon ?

Whats the performance cost of using this on a 20 digit code across 31M records. 

[Chanty4u]

Hi..

Yes it's a good choice to use 

LOAD

    Code,

    Hash128(Code) as CodeHash

FROM ...;..

Or if you use composite key .Hash128(CustomerID, ProductID, Date) as Key

For faster joins and clean model