pg_shadow
   The view pg_shadow exists for backwards
   compatibility: it emulates a catalog that existed in
   PostgreSQL before version 8.1.
   It shows properties of all roles that are marked as
   rolcanlogin in
   pg_authid.
  
   The name stems from the fact that this table
   should not be readable by the public since it contains passwords.
   pg_user
   is a publicly readable view on
   pg_shadow that blanks out the password field.
  
Table 52.87. pg_shadow Columns
| Name | Type | References | Description | 
|---|---|---|---|
| usename | name |  | User name | 
| usesysid | oid |  | ID of this user | 
| usecreatedb | bool | User can create databases | |
| usesuper | bool | User is a superuser | |
| userepl | bool | User can initiate streaming replication and put the system in and out of backup mode. | |
| usebypassrls | bool | User bypasses every row level security policy, see Section 5.7 for more information. | |
| passwd | text | Password (possibly encrypted); null if none.  See pg_authidfor details of how encrypted passwords are stored. | |
| valuntil | abstime | Password expiry time (only used for password authentication) | |
| useconfig | text[] | Session defaults for run-time configuration variables |