50.8. pg_authid

The catalog pg_authid contains information about database authorization identifiers (roles). A role subsumes the concepts of users and groups. A user is essentially just a role with the rolcanlogin flag set. Any role (with or without rolcanlogin) can have other roles as members; see pg_auth_members.

Since this catalog contains passwords, it must not be publicly readable. pg_roles is a publicly readable view on pg_authid that blanks out the password field.

Chapter 20 contains detailed information about user and privilege management.

Because user identities are cluster-wide, pg_authid is shared across all databases of a cluster: there is only one copy of pg_authid per cluster, not one per database.

Table 50.8. pg_authid Columns

NameTypeDescription
oidoidRow identifier (hidden attribute; must be explicitly selected)
rolnamenameRole name
rolsuperboolRole has superuser privileges
rolinheritboolRole automatically inherits privileges of roles it is a member of
rolcreateroleboolRole can create more roles
rolcreatedbboolRole can create databases
rolcanloginbool Role can log in. That is, this role can be given as the initial session authorization identifier
rolreplicationbool Role is a replication role. A replication role can initiate replication connections and create and drop replication slots.
rolbypassrlsbool Role bypasses every row level security policy, see Section 5.7 for more information.
rolconnlimitint4 For roles that can log in, this sets maximum number of concurrent connections this role can make. -1 means no limit.
rolpasswordtext Password (possibly encrypted); null if none. The format depends on the form of encryption used.
rolvaliduntiltimestamptzPassword expiry time (only used for password authentication); null if no expiration

For an MD5 encrypted password, rolpassword column will begin with the string md5 followed by a 32-character hexadecimal MD5 hash. The MD5 hash will be of the user's password concatenated to their user name. For example, if user joe has password xyzzy, Postgres Pro will store the md5 hash of xyzzyjoe.

If the password is encrypted with SCRAM-SHA-256, it has the format:

SCRAM-SHA-256$<iteration count>:<salt>$<StoredKey>:<ServerKey>

where salt, StoredKey and ServerKey are in Base64 encoded format. This format is the same as that specified by RFC 5803.

A password that does not follow either of those formats is assumed to be unencrypted.