51.8. pg_authid#
The catalogpg_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 therolcanlogin flag set. Any role (with or withoutrolcanlogin) can have other roles as members; seepg_auth_members.
Since this catalog contains passwords, it must not be publicly readable.pg_roles is a publicly readable view onpg_authid that blanks out the password field.
Chapter 21 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 ofpg_authid per cluster, not one per database.
Table 51.8. 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, seeSection 5.9 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 stringmd5 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 userjoe has passwordxyzzy,PostgreSQL will store the md5 hash ofxyzzyjoe.
If the password is encrypted with SCRAM-SHA-256, it has the format:
SCRAM-SHA-256$<iteration count>:<salt>$<StoredKey>:<ServerKey>
wheresalt,StoredKey andServerKey are in Base64 encoded format. This format is the same as that specified byRFC 5803.
A password that does not follow either of those formats is assumed to be unencrypted.