Most multi-user software that relies on a database uses a single set of credentials to access the database. Access permissions are defined and enforced within application logic, and the database server knows nothing about the users, their roles or permissions.Postgraphile allows front-end code to use graphql to access data stored in a postgres database. So there's no traditional backend code to do the work of storing and enforcing user/role-based authorisation for certain data.The recommended way to handle this is by the use of Row-Level Security (RLS), a database feature which ensures that only permitted data is updated or returned, based on the end user who generated the query. [0]This sounds fine in principle but, because permissions are at row-level, you can't have different permissions for different columns in the same table. The solution is to split your tables into multiple, narrower tables. So, for example, if you don't want a user to be able to update their own username, the username column could be in a separate table from other demographic information.I understand this in theory, and I know that RLS isn't new and isn't restricted to postgraphile. But I'd love to see a non-trivial example of it in use, for an app whose only backend is a database (ideally postgres and postgraphile, but really any relational database that supports RLS would be fine).Can anyone point to a good repo or book that has a good example of schema design using RLS?(I spent some time searching, but didn't find anything promising.)[0] 