pg_available_extension_versions view lists the
specific extension versions that are available for installation.
See also the
catalog, which shows the extensions currently installed.
True if this version of this extension is currently installed
True if only superusers are allowed to install this extension
True if the extension can be installed by non-superusers with appropriate privileges
True if extension can be relocated to another schema
Name of the schema that the extension must be installed into,
Names of prerequisite extensions,
Comment string from the extension's control file
pg_available_extension_versions view is read