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 22 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 55.9. pg_authid
Columns
Column Type Description |
---|
Row identifier |
Role name |
Role has superuser privileges |
Role automatically inherits privileges of roles it is a member of |
Role can create more roles |
Role can create databases |
Role can log in. That is, this role can be given as the initial session authorization identifier. |
Role is a replication role. A replication role can initiate replication connections and create and drop replication slots. |
Role bypasses every row-level security policy, see Section 5.8 for more information. |
For roles that can log in, this sets maximum number of concurrent connections this role can make. -1 means no limit. |
Password (possibly encrypted); null if none. The format depends on the form of encryption used. |
Password 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
, PostgreSQL
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.