create or replace function struct_merge_patch(base, update) as (
<syntaxhighlight lang="sql">
  with cte as (
    from (select unnest(update))
          positional join
          (select COLUMNS(x -> x not in json_keys(update::JSON)) from (select unnest(base)))
   )
   select cte from cte
);

select struct_merge_patch( getvariable('base'), getvariable('update')) as merged;