Re: Add %r substitution for psql prompts to show recovery status

On 1/9/18 15:36, Peter Eisentraut wrote:
> On 12/7/17 19:54, Tatsuo Ishii wrote:
>>> On Wed, Dec 6, 2017 at 9:19 PM, Ian Barwick <ian.barwick@2ndquadrant.com> wrote:
>>>> Note this substitution sends a "pg_is_in_recovery()" query to the server
>>>> each time it's encountered; unless there's something I'm overlooking I
>>>> think that's the only reliable way to determine current recovery status.
>>>
>>> That seems kinda painful.
>>>
>>> And what happens in an aborted transaction?
>>
>> Yeah. I think we need some from help backend for this. For example, a
>> parameter status message can be used here.  If PostgreSQL moves to the
>> recovery state or vice versa, PostgreSQL sends the parameter status
>> message to frontend.
> 
> I agree a backend status message is the right way to do this.
> 
> We could perhaps report transaction_read_only, if we don't want to add a
> new one.

I'm setting this CF item to returned with feedback, since it would
apparently be a much bigger change than then initial patch.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services