The pg_authid table contains information about database authorization identifiers (roles). A role subsumes the concepts of users and groups. A user is a role with the rolcanlogin flag set. Any role (with or without rolcanlogin) may 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.

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

column type references description
oid oid   Row identifier (hidden attribute; must be explicitly selected)
rolname name   Role name
rolsuper boolean   Role has superuser privileges
rolinherit boolean   Role automatically inherits privileges of roles it is a member of
rolcreaterole boolean   Role may create more roles
rolcreatedb boolean   Role may create databases
rolcatupdate boolean   Role may update system catalogs directly. (Even a superuser may not do this unless this column is true)
rolcanlogin boolean   Role may log in. That is, this role can be given as the initial session authorization identifier
rolreplication boolean   Role is a replication role. That is, this role can initiate streaming replication and set/unset the system backup mode using pg_start_backup and pg_stop_backup.
rolconnlimit int4   For roles that can log in, this sets maximum number of concurrent connections this role can make. -1 means no limit
rolpassword text   Password (possibly encrypted); NULL if none. The format depends on the form of encryption used.1
rolvaliduntil timestamptz   Password expiry time (only used for password authentication); NULL if no expiration
rolresqueue oid   Object ID of the associated resource queue ID in pg_resqueue
rolcreaterextgpfd boolean   Privilege to create read external tables with the gpfdist or gpfdists protocol
rolcreaterexhttp boolean   Privilege to create read external tables with the http protocol
rolcreatewextgpfd boolean   Privilege to create write external tables with the gpfdist or gpfdists protocol
rolresgroup oid   Object ID of the associated resource group ID in pg_resgroup


  • 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 Greenplum Database will store the md5 hash of xyzzyjoe.

  • If the password is encrypted with SCRAM-SHA-256, the rolpassword column 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.

  • If the password is encrypted with SHA-256, the rolpassword column is a 64-byte hexadecimal string prefixed with the characters sha256.

A password that does not follow any of these formats is assumed to be unencrypted.

Parent topic: System Catalogs Definitions

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