Create an immutable clone of concat_ws
问题 This blog post shows an example of how to create a immutable_concat function in Pg: CREATE OR REPLACE FUNCTION immutable_concat(VARIADIC "any") RETURNS text AS 'text_concat' LANGUAGE internal IMMUTABLE I'd like to do the same with concat_ws and the corresponding text_concat_ws does exist, however, the following just crashes the process: CREATE OR REPLACE FUNCTION immutable_concat_ws(VARIADIC "any") RETURNS text AS 'text_concat_ws' LANGUAGE internal IMMUTABLE Update: The siguature of immutable