What method is used to implement row-level security based on roles in a security predicate?

Utilizing the Flatten transformation to store user IDs in a hierarchy is a sound method for implementing row-level security based on roles in a security predicate. This approach allows you to represent the relationships between users and their roles, effectively creating a structure that can enforce security rules at the row level. By flattening this hierarchy, you can simplify access management by distinguishing user IDs and their associated roles in a way that makes it easier to apply filters based on user access.

Implementing a hierarchical structure is crucial for row-level security because it enables more granular control over data visibility depending on the user's role. When access controls are modeled in a hierarchy, it becomes straightforward to query against this structure and tailor data access accordingly. Flattening this structure allows for efficient and effective application of security predicates, as it provides a clear mapping of which users belong to which roles and what data they should be allowed to access.

In contrast, creating a new column for roles or duplicating datasets does not efficiently leverage the benefits of hierarchical relationships or may lead to data redundancy, complicating data management. Moreover, applying a filter directly to the dataset without transformations may not adequately reflect the complex interdependencies of user roles and data accessibility, making it harder to maintain consistent security policies across different user groups.