The view pg_user provides access to
   information about database users.  This is simply a publicly
   readable view of 
   pg_shadow
   that blanks out the password field.
  
Table 43-50. pg_user Columns
| Name | Type | Description |  | 
|---|
| usename | name | User name |  | 
| usesysid | int4 | User ID (arbitrary number used to reference this user) |  | 
| usecreatedb | bool | User may create databases |  | 
| usesuper | bool | User is a superuser |  | 
| usecatupd | bool | User may update system catalogs.  (Even a superuser may not do
       this unless this column is true.) |  | 
| passwd | text | Not the password (always reads as ********) |  | 
| valuntil | abstime | Password expiry time (only used for password authentication) |  | 
| useconfig | text[] | Session defaults for run-time configuration variables |  |