Hash Collision percentage on HASHBYTES SHA2_512

Question

Hello, we are trying to move a large table and want to confirm the varbinary values do not change (or at least capture it if it changes). We plan to use below query:

select ID, HASHBYTES('SHA2_512', cast(blob AS VARBINARY(8000))) from BlobTable;

I understand it is possible to have the same hashvalue even for different inputs in hash collision.

Would Microsoft know what is the percentage this could happen?

Answer 1

Hi @Larimore Suanque ，

Please refer below links and check whether they are helpful to you. Thanks.

Choosing the right algorithm in HashBytes function
Hash Collision Probabilities

If the response is helpful, please click "Accept Answer" and upvote it.

Best regards
Melissa