View the permissions and related views of a user in Oracle

Query roles of a user:
Select grantee, granted_role from dba_role_privs where grantee = 'wjw ';
Query the system permissions of a user:
Select grantee, privilege from dba_sys_privs where grantee = 'wjw ';
Query the system permissions of a role:
Select privilege from role_sys_privs where role = 'resource ';
Queries the roles in a role.
Select granted_role from role_role_privs where role = 'sysdb ';

If you want a user to viewDatabaseData Dictionary permission, but you do not have the system permission or permissions for user data.ManagementUseful Personnel)
Grant create session, select_catalog_role to wjw;

Users, roles, and permissionsDBAView:
Dba_users provides user information
Dba_roles: displays all roles in the database
Dba_col_privs displays column-level object authorization
Dba_role_privs displays users and Roles
Dba_sys_privs: displays the users granted system permissions.
Dba_tab_privs displays users and their permissions on the table
Role_role_privs
Role_sys_privs displays the system permissions granted to the role
Role_tab_privs displays the table permissions granted to the role
Session_privs: displays the permissions that can be used by users.
Session_roles: displays the roles currently available to users.

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