RE: Libpq support to connect to standby server as priority

From: Robert Haas [mailto:robertmhaas@gmail.com]
> I really dislike having both target_sesion_attrs and
> target_server_type.  It doesn't solve any actual problem.  master,
> slave, prefer-save, or whatever you like could be put in
> target_session_attrs just as easily, and then we wouldn't end up with
> two keywords doing closely related things.  'master' is no more or
> less a server attribute than 'read-write'.

Hmm, that may be OK.  At first, I felt it strange to treat the server type (primary or standby) as a session attribute.
But we can see the server type as one attribute in a sense that a session is established for.  I'm inclined to agree
with:

target_session_attr = {any | read-write | read-only | prefer-read | primary | standby | prefer-standby}


Regards
Takayuki Tsunakawa