Providing catalog view to pg_hba.conf file - Patch submission

Hi,

In connection to my previous proposal about "providing catalog view to
pg_hba.conf file contents" , I have developed the attached patch .

[Current situation]

Currently, to view the pg_hba.conf file contents, DB admin has to access
the file from database server to read the settings. In case of huge and
multiple hba files, finding the appropriate hba rules which are loaded
will be difficult and take some time.

[What this Patch does]

Functionality of the attached patch is that it will provide a new view
"pg_hba_settings" to admin users. Public access to the view is
restricted. This view will display basic information about HBA setting
details of postgresql cluster. Information to be shown , is taken from
parsed hba lines and not directly read from pg_hba.conf files.
Documentation files are also updated to include details of this new view
under "Chapter 47.System Catalogs". Also , a new note is added in
"chapter 19.1 The pg_hba.conf File"

[Advantage]

Advantage of having this "pg_hba_settings" view is that the admin can
check, what hba rules are loaded in runtime via database connection
itself. And, thereby it will be easy and useful for admin to check all
the users with their privileges in a single view to manage them.

Thanks & Regards,

Vaishnavi

Fujitsu Australia