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.
|oid||oid||Row identifier (hidden attribute; must be explicitly selected)|
|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. If the password is encrypted, this column will begin with the string md5 followed by a 32-character hexadecimal MD5 hash. The MD5 hash will be 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. Greenplum assumes that a password that does not follow that format is unencrypted.|
|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|