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.
|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 5.7 for more information.|
|Password (possibly encrypted); null if none. See pg_authid for details of how encrypted passwords are stored.|
|Password expiry time (only used for password authentication)|
|Session defaults for run-time configuration variables|