51.86. 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 51.87. 
    
     pg_shadow
    
    Columns
   
  
| Column Type Description | 
|---|
| 
         User name | 
| 
         ID of this user | 
| 
         User can create databases | 
| 
         User is a superuser | 
| 
         User can initiate streaming replication and put the system in and out of backup mode. | 
| 
         User bypasses every row level security policy, see Section 5.8 for more information. | 
| 
         
        Encrypted password; null if none.  See
        
          | 
| 
         Password expiry time (only used for password authentication) | 
| 
         Session defaults for run-time configuration variables |