PostgreSQL provides a set of predefined roles that provide access to certain, commonly needed, privileged capabilities and information. Administrators (including roles that have the CREATEROLE privilege) can GRANT these roles to users and/or other roles in their environment, providing those users with access to the specified capabilities and information. For example:
GRANT pg_signal_backend TO admin_user;
Care should be taken when granting these roles to ensure they are only used where needed and with the understanding that these roles grant access to privileged information.
The predefined roles are described below. Note that the specific permissions for each of the roles may change in the future as additional capabilities are added. Administrators should monitor the release notes for changes.
pg_checkpoint #pg_checkpoint allows executing the CHECKPOINT command.
pg_create_subscription #pg_create_subscription allows users with CREATE permission on the database to issue CREATE SUBSCRIPTION.
pg_database_owner #pg_database_owner always has exactly one implicit member: the current database owner. It cannot be granted membership in any role, and no role can be granted membership in pg_database_owner. However, like any other role, it can own objects and receive grants of access privileges. Consequently, once pg_database_owner has rights within a template database, each owner of a database instantiated from that template will possess those rights. Initially, this role owns the public schema, so each database owner governs local use of that schema.
pg_maintain #pg_maintain allows executing VACUUM, ANALYZE, CLUSTER, REFRESH MATERIALIZED VIEW, REINDEX, and LOCK TABLE on all relations, as if having MAINTAIN rights on those objects.
pg_monitorpg_read_all_settingspg_read_all_statspg_stat_scan_tables #These roles are intended to allow administrators to easily configure a role for the purpose of monitoring the database server. They grant a set of common privileges allowing the role to read various useful configuration settings, statistics, and other system information normally restricted to superusers.
pg_monitor allows reading/executing various monitoring views and functions. This role is a member of pg_read_all_settings, pg_read_all_stats and pg_stat_scan_tables.
pg_read_all_settings allows reading all configuration variables, even those normally visible only to superusers.
pg_read_all_stats allows reading all pg_stat_* views and use various statistics related extensions, even those normally visible only to superusers.
pg_stat_scan_tables allows executing monitoring functions that may take ACCESS SHARE locks on tables, potentially for a long time (e.g., pgrowlocks(text) in the pgrowlocks extension).
pg_read_all_datapg_write_all_data #pg_read_all_data allows reading all data (tables, views, sequences), as if having SELECT rights on those objects and USAGE rights on all schemas. This role does not bypass row-level security (RLS) policies. If RLS is being used, an administrator may wish to set BYPASSRLS on roles which this role is granted to.
pg_write_all_data allows writing all data (tables, views, sequences), as if having INSERT, UPDATE, and DELETE rights on those objects and USAGE rights on all schemas. This role does not bypass row-level security (RLS) policies. If RLS is being used, an administrator may wish to set BYPASSRLS on roles which this role is granted to.
pg_read_server_filespg_write_server_filespg_execute_server_program #These roles are intended to allow administrators to have trusted, but non-superuser, roles which are able to access files and run programs on the database server as the user the database runs as. They bypass all database-level permission checks when accessing files directly and they could be used to gain superuser-level access. Therefore, great care should be taken when granting these roles to users.
pg_read_server_files allows reading files from any location the database can access on the server using COPY and other file-access functions.
pg_write_server_files allows writing to files in any location the database can access on the server using COPY and other file-access functions.
pg_execute_server_program allows executing programs on the database server as the user the database runs as using COPY and other functions which allow executing a server-side program.
pg_signal_autovacuum_worker #pg_signal_autovacuum_worker allows signaling autovacuum workers to cancel the current table's vacuum or terminate its session. See Section 9.28.2.
pg_signal_backend #pg_signal_backend allows signaling another backend to cancel a query or terminate its session. Note that this role does not permit signaling backends owned by a superuser. See Section 9.28.2.
pg_use_reserved_connections #pg_use_reserved_connections allows use of connection slots reserved via reserved_connections.