RE: [Proposal] Add foreign-server health checks infrastructure

Dear Katsuragi-san,

Thank you for reviewing! PSA new version patches.

> I think we can update the status to ready for committer after
> this fix, if there is no objection.

That's a very good news for me! How about other people?

> >> 7. the document of postgres_fdw_verify_connection_states_all
> >> <literal>NULL</literal>
> >> + is returned if the local session does not have connection
> >> caches,
> >> or this
> >> + function is not available on this platform.
> >>
> >> I think there is a case where a connection cache exists but valid
> >> connections do not exist and NULL is returned (disconnection case).
> >> Almost the same document as the postgres_fdw_verify_connection_states
> >> case (comment no.5) seems better.
> >
> > Yes, but completely same statement cannot be used because these is not
> > specified foreign server. How about:
> > NULL is returned if there are no established connections or this
> > function ...
>
> Yes, to align with the postgres_fdw_verify_connection_states()
> case, how about writing the connection is not valid. Like the
> following?
> 'NULL is returned if no valid connections are established or
> this function...'

Prefer yours, fixed.

> This is my comment for v35. Please check.
> 0002:
> 1. the comment of verify_cached_connections (I missed one minor point.)
> + * This function emits warnings if a disconnection is found. This
> returns true
> + * if disconnections cannot be found, otherwise returns false.
>
> I think false is returned only if disconnections are found and
> true is returned in all other cases. So, modifying the description
> like the following seems better.
> 'This returns false if disconnections are found, otherwise
> returns true.'

Fixed.

Best Regards,
Hayato Kuroda
FUJITSU LIMITED