Re: display hot standby state in psql prompt

Nathan Bossart <nathandbossart@gmail.com>

From: Nathan Bossart <nathandbossart@gmail.com>

To: Jim Jones <jim.jones@uni-muenster.de>

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>

Date: 2025-10-27T16:23:12Z

Lists: pgsql-hackers

Commits

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psql: Add %i prompt escape to indicate hot standby status.
- dddbbc253b92 19 (unreleased) landed
Mark search_path as GUC_REPORT
- 28a1121fd912 18.0 cited

On Mon, Oct 27, 2025 at 09:08:17AM +0100, Jim Jones wrote:
> +            Displays the session's read-only status as <literal>read-only</literal>
> +            if the server is in hot standby (<literal>in_hot_standby</literal> is
> +            <literal>on</literal>) or the default transaction mode is read-only
> +            (<literal>default_transaction_read_only</literal> is <literal>on</literal>),
> +            or <literal>read-write</literal> otherwise. Useful for identifying
> +            sessions that cannot perform writes, such as in replication setups.

This was briefly mentioned upthread, but I'm a little concerned that this
doesn't respond to commands like SET TRANSACTION READ ONLY.  I wonder if we
should mark transaction_read_only as GUC_REPORT and use that instead.  FWIW
I see that we marked search_path as GUC_REPORT somewhat recently (see
commit 28a1121).

-- 
nathan