.psqlrc

-- for debug purposes
\set pid 'SELECT pg_backend_pid();'
\set gdb 'SELECT pg_backend_pid() \\g |pg_debug'

-- for beautiful prompt
select (
	with
	preferred_settings as (
		select * from (
			values
				/*
				 * Put your lines here.
				 *   format: (position, name, format_string, default_value)
				 *   format_string:
				 *     empty string: show only value
				 *     single char:  show value prepended by char, e.g. '#1'
				 *     otherwise:    show name-value pair, e.g. 'port=5432'
				 *   default_value: hide setting if value = default_value
				 */
				(1, 'master_or_replica', '', 'M'),
				(2, 'port', 'port', '5432'),
				(3, 'shardman.my_id', '@', NULL),
				(4, 'multimaster.node_id', '@', NULL)
		) as v(id, name, short_name, default_value)
	),
	settings as (
		/* global settings */
		select name, setting from pg_catalog.pg_settings
		union
		/* put your custom setting providers here */
		select
			'master_or_replica' as name,
			case
				when pg_is_in_recovery() then 'R'
				else 'M'
				end as setting
	),
	config as (
		select
			id,
			case
				when short_name = '' then
					setting
				when char_length(short_name) = 1 then
					short_name || setting
				when short_name is null then
					name || '=' || setting
				else
					short_name || '=' || setting
			end as kvp
		from settings join preferred_settings using(name)
		where
			preferred_settings.default_value is null OR
			preferred_settings.default_value != setting
	)
	select '[' || string_agg(kvp, ', ' order by id) || ']' from config
) as prompt_hints
\gset

-- prompt itself
\set PROMPT1 '%/%:prompt_hints:=# '

-- it's nice to see execution time
\timing on