Re: display hot standby state in psql prompt

Andreas Karlsson <andreas@proxel.se>

From: Andreas Karlsson <andreas@proxel.se>

To: Jim Jones <jim.jones@uni-muenster.de>, Nathan Bossart <nathandbossart@gmail.com>

Cc: Fujii Masao <masao.fujii@gmail.com>, Srinath Reddy Sadipiralla <srinath2133@gmail.com>, Greg Sabino Mullane <htamfids@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Chao Li <li.evan.chao@gmail.com>

Date: 2025-11-08T08:57:13Z

Lists: pgsql-hackers

On 10/31/25 10:00 PM, Jim Jones wrote:
> Thoughts on this approach?

I am not a fan at all of introducing running a query when calculating 
the prompt. Imagine if there are network issues or otherwise and in 
general I imagine that the prompt can send a query would be highly 
surprising to most users.

I personally lean towards that maybe we should keep it simple and go 
back to the origins of the patch which just tried to show if it is a 
standby or not given how complex it is to tell that we are in read-only 
or not. The alternative would be to update the protocol so the client if 
informed if a transaction is read-only or not but I do not think it 
would be possible to convince people to update the protocol just for 
psql. Maybe if some connection pooler would also be interest but I am 
not sure what they would need this for.

Andreas