Guys; This errors out with:
ERROR: could not determine which collation to use for string comparison
HINT: Use the COLLATE clause to set the collation explicitly.
The database is init'ed with:
initdb -D $PGDATA -E utf8 --locale=nb_NO.UTF-8
13-dev HEAD as of 8128b0c152a67917535f50738ac26da4f984ddd9
Works fine in <= 12
===========================
create table person( id serial primary key, firstname varchar, lastname varchar
);
insert into person(firstname, lastname) values ('Andreas', 'Krogh');
CREATE OR REPLACE FUNCTION concat_lower(varchar, varchar) RETURNS varchar AS
$$
SELECT nullif(lower(coalesce($1, '')) || lower(coalesce($2, '')), '')
$$ LANGUAGE SQL
IMMUTABLE;
select * from person pers ORDER BY concat_lower(pers.firstname, pers.lastname) ASC;
===========================