Re: Libpq support to connect to standby server as priority

On Thu, Mar 21, 2019 at 2:26 AM Haribabu Kommi <kommi(dot)haribabu(at)gmail(dot)com> wrote:
> 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?

I think it will be best to have one set of attributes that check
default_transaction_read_only and a differently-named set that check
pg_is_in_recovery(). For each, there should be one value that looks
for a 'true' return and one value that looks for a 'false' return and
perhaps values that accept either but prefer one or the other.

IOW, there's no reason to make primary an alias for read-write. If
you want read-write, you can just say read-write. But we can make
'primary' or 'master' look for a server that's not in recovery and
'standby' look for one that is.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company