Hi hackers,
I'm sure I'm not the only one who can never remember which way around
the value and delimiter arguments go for string_agg() and has to look it
up in the manual every time. To make it more convenient, here's a patch
that adds proargnames to its pg_proc entries so that it can be seen with
a quick \df in psql.
I also added names to json(b)_object_agg() for good measure, even though
they're more obvious. The remaining built-in multi-argument aggregate
functions are the stats-related ones, where it's all just Y/X (but why
in that order?), so I didn't think it was necessary. If others feel more
strongly, I can add those too.
- ilmari
>From 73f323d5e97dca2e2452f5be199864a8358559c5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dagfinn=20Ilmari=20Manns=C3=A5ker?= <ilm...@ilmari.org>
Date: Mon, 27 Feb 2023 13:06:29 +0000
Subject: [PATCH] Add argument names to multi-argument aggregates
This makes it easier to see which way around the arguments go when
using \dfa. This is particularly relevant for string_agg(), but add
it to json(b)_object_agg() too for good measure.
---
src/include/catalog/pg_proc.dat | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index e2a7642a2b..f96d29278f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -4988,6 +4988,7 @@
{ oid => '3538', descr => 'concatenate aggregate input into a string',
proname => 'string_agg', prokind => 'a', proisstrict => 'f',
prorettype => 'text', proargtypes => 'text text',
+ proargnames => '{value,delimiter}',
prosrc => 'aggregate_dummy' },
{ oid => '3543', descr => 'aggregate transition function',
proname => 'bytea_string_agg_transfn', proisstrict => 'f',
@@ -5000,6 +5001,7 @@
{ oid => '3545', descr => 'concatenate aggregate input into a bytea',
proname => 'string_agg', prokind => 'a', proisstrict => 'f',
prorettype => 'bytea', proargtypes => 'bytea bytea',
+ proargnames => '{value,delimiter}',
prosrc => 'aggregate_dummy' },
# To ASCII conversion
@@ -8899,6 +8901,7 @@
{ oid => '3197', descr => 'aggregate input into a json object',
proname => 'json_object_agg', prokind => 'a', proisstrict => 'f',
provolatile => 's', prorettype => 'json', proargtypes => 'any any',
+ proargnames => '{key,value}',
prosrc => 'aggregate_dummy' },
{ oid => '3198', descr => 'build a json array from any inputs',
proname => 'json_build_array', provariadic => 'any', proisstrict => 'f',
@@ -9791,6 +9794,7 @@
{ oid => '3270', descr => 'aggregate inputs into jsonb object',
proname => 'jsonb_object_agg', prokind => 'a', proisstrict => 'f',
prorettype => 'jsonb', proargtypes => 'any any',
+ proargnames => '{key,value}',
prosrc => 'aggregate_dummy' },
{ oid => '3271', descr => 'build a jsonb array from any inputs',
proname => 'jsonb_build_array', provariadic => 'any', proisstrict => 'f',
--
2.39.1
