As you may remember, Azure SQL Data Warehouse - Microsoft's cloud relational database solution - saw a three-fold increase in compute scale last year. This brought with it unlimited columnar storage, and now there's support for column-level security.
In its most basic definition, the rather self-explanatory column-level security capability allows admins to limit which employees can view which column of the database. For example, SSNs or a person's other personally identifiable information can only be viewed by those who handle this kind of data, thanks to this ability to tweak permissions. It also means that the overall security approach can be simplified without the need to fundamentally redesign the entire database or introduce additional views that filter out certain columns.
Admins can control user permission using the GRANT T-SQL statement, thus creating a security policy for per-column access. If this is something you might be interested in checking in out, the feature is available free of charge today in all Azure regions. More information about SQL Data Warehouse - including pricing - is available at the relevant Azure portal.