BUG #18443: jsonb_agg issue. Again.

On Fri, Apr 19, 2024 at 8:25 AM PG Bug reporting form <
noreply@postgresql.org> wrote:

The following bug has been logged on the website:

Bug reference: 18443
Logged by: Alexander Tsaregorodtsev
Email address: pfunk@mail.ru
PostgreSQL version: 12.18
Operating system: Official docker container
Description:

Greetings!
Is it expected behavior?

--simple function raising ONE notice and returning record of 2 int`s
drop function if exists public.out2(jsonb);
create or replace function public.out2(_in jsonb, a out int, b out int)
returns record
as
$body$
begin
raise notice '***';
end;
$body$
language plpgsql;

--similar function raising notice but returning record of 3 int`s
drop function if exists public.out3();
create or replace function public.out3(_in jsonb, a out int, b out int, c
out int)
returns record

--Problem! function out2 has invoked 2 times (two NOTICE`s and accidentally
number of output parameters)
select (public.out2(jsonb_agg(jsonb_build_object('col', col)))).* --,
jsonb_agg(jsonb_build_object('col', col))
from tmp_view;

You wrote a table-producing function (one row but three columns). Those
need [1] to be executed in the FROM clause, via an implicit or explicit
LATERAL join if you have data from other relations being fed in as input
arguments.

David J.

1. well, at least if you don't want to see this kind of artifact where the
way to expand .* is to copy the expression preceding it.

You wrote a table-producing function (one row but three columns).  Those need [1] to be executed in the FROM clause, via an implicit or explicit LATERAL join if you have data from other relations being fed in as input arguments.
 
David J.
 
1. well, at least if you don't want to see this kind of artifact where the way to expand .* is to copy the expression preceding it.
 

Do you mean select (out3).* .. equal to select (out3).col1, (out3).col3, (out3).col3 … ?
Didn`t even suppose that..
Sometimes I've used (row).col or (row).* in select list.
Would be appreciated if you could provide keywords for googling.
And yeah, after hours of confusion rewrote it to:
 
select o.*
from 
  (select jsonb_agg(t) as jsonbagg from tmp_view t) j
  , lateral public.out3(j.jsonbagg) o;
 
And it works just fine!
 
 

You wrote a table-producing function (one row but three columns).  Those need [1] to be executed in the FROM clause, via an implicit or explicit LATERAL join if you have data from other relations being fed in as input arguments.

David J.

1. well, at least if you don't want to see this kind of artifact where the way to expand .* is to copy the expression preceding it.

Do you mean select (out3).* .. equal to select (out3).col1, (out3).col3, (out3).col3 … ?
Didn`t even suppose that..
Sometimes I've used (row).col or (row).* in select list.
Would be appreciated if you could provide keywords for googling.

 
 
Of course semantically it is equal).Never mind. 
 
 
 
 

=?UTF-8?B?0KY=?= <pfunk@mail.ru> writes:

You wrote a table-producing function (one row but three columns).  Those need [1] to be executed in the FROM clause, via an implicit or explicit LATERAL join if you have data from other relations being fed in as input arguments.

1. well, at least if you don't want to see this kind of artifact where the way to expand .* is to copy the expression preceding it.

Do you mean select (out3).* .. equal to select (out3).col1, (out3).col3, (out3).col3 … ?
Didn`t even suppose that..
Sometimes I've used (row).col or (row).* in select list.
Would be appreciated if you could provide keywords for googling.

The main documentation about SELECT lists is

https://www.postgresql.org/docs/current/queries-select-lists.html

which points you to

https://www.postgresql.org/docs/current/rowtypes.html#ROWTYPES-USAGE

where there's a Tip explaining exactly this point.

regards, tom lane