On 9/14/21 10:10 PM, A Z wrote:
-In PostgreSQL, what is the difference between Roles, Groups, and Policies exactly? What are they each, how do they relate to one another, and which one(s) can be assigned to another?
Roles, groups and users have to do with project history more then anything else. Prior to version 8.1 there where no roles, just users and groups. Roles when introduced they subsumed users and groups. As David mentioned then the convention became that a role that had login was equivalent to a user and one that did not was a group. This is called out in the documentation for the aliases CREATE GROUP and CREATE USER, both of which actually point at CREATE ROLE.
Policies comes into play by allowing for more granular control over what a role can do on a table.
-- Adrian Klaver adrian.klaver@xxxxxxxxxxx