Re: Libpq support to connect to standby server as priority

On Wed, Mar 20, 2019 at 5:01 PM Tsunakawa, Takayuki <
tsunakawa(dot)takay(at)jp(dot)fujitsu(dot)com> wrote:

> From: Robert Haas [mailto:robertmhaas(at)gmail(dot)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}
>

Thanks for your suggestions.

Based on the above new options that can be added to target_session_attrs,

primary - it is just an alias to the read-write option.
standby, prefer-standby - These options should check whether server is
running in recovery mode or not
instead of checking whether server accepts read-only connections or not?

Regards,
Haribabu Kommi
Fujitsu Australia