The view usage_privileges identifies USAGE privileges granted on various kinds of objects to a currently enabled role or by a currently enabled role. In PostgreSQL, this currently applies to collations, domains, foreign-data wrappers, foreign servers, and sequences. There is one row for each combination of object, grantor, and grantee.
Since collations do not have real privileges in PostgreSQL, this view shows implicit non-grantable USAGE privileges granted by the owner to PUBLIC for all collations. The other object types, however, show real privileges.
In PostgreSQL, sequences also support SELECT and UPDATE privileges in addition to the USAGE privilege. These are nonstandard and therefore not visible in the information schema.
Table 34-55. usage_privileges Columns
|grantor||sql_identifier||Name of the role that granted the privilege|
|grantee||sql_identifier||Name of the role that the privilege was granted to|
|object_catalog||sql_identifier||Name of the database containing the object (always the current database)|
|object_schema||sql_identifier||Name of the schema containing the object, if applicable, else an empty string|
|object_name||sql_identifier||Name of the object|
|object_type||character_data||COLLATION or DOMAIN or FOREIGN DATA WRAPPER or FOREIGN SERVER or SEQUENCE|
|is_grantable||yes_or_no||YES if the privilege is grantable, NO if not|