question Re: Hadoop data linking from multiple sources in Archives of Support Questions (Read Only)

Hadoop data linking from multiple sources

learninghuman — Wed, 29 Jun 2016 05:13:43 GMT

Data comes from multiple sources and these are exposed in the hive table for the users. A specific column is sensitive and needs to be given restricted access. If a user who wants to join 2 such tables on the column that he does not have access to, then whats the best approach to make it work? One option is to link the sensitive column with a generated key so that the user can join on the generated key. Is this a good idea or any better idea?

Re: Hadoop data linking from multiple sources

bleonhardi — Wed, 29 Jun 2016 19:36:11 GMT

You could create a hashed column for that key and choose the hash algorithm in a way that a hash collision is very unlikely. However I don't get the usecase completely. Couldn't you just create a new View that already joins the two tables together and only give access to the resulting columns?

Table A ( customers web site a )

Name, Address, CreditCard

Table B ( customers web site b )

Name, Address, CreditCard

Create View C as

SELECT NameA,AddressA, NameB, AddressB from A,B where a.CreditCard = B.CreditCard;

And only give access to that view. I know this doesn't give the same flexibility but you do not need to do the whole hash thing.

If more flexibility is desired then your proposed approach of adding a masked column to both tables would be the way to go. I would think something like sha2 or the aes_encrypt function should provide a way to be very secure in avoiding hash collisions.

Re: Hadoop data linking from multiple sources

learninghuman — Wed, 29 Jun 2016 20:00:25 GMT

@Benjamin Leonhardi Thanks, makes sense