How to grant privileges to a user in Oracle

Grant a system privilege, an object privilege, or a role to a user, then confirm what landed.

This grants privileges. Prefer a role, grant only what is needed, and review before running.

-- System privilege
GRANT CREATE SESSION TO &&username;

-- Object privilege (owner.table)
GRANT SELECT ON &owner..&table_name TO &username;

-- Role
-- GRANT <app_role> TO &username;

-- Verify (read-only): system privileges, then object privileges
SELECT privilege
FROM   dba_sys_privs
WHERE  grantee = UPPER('&username')
ORDER  BY privilege;

SELECT owner, table_name, privilege
FROM   dba_tab_privs
WHERE  grantee = UPPER('&username')
ORDER  BY owner, table_name, privilege;