There is no way to call UDF SQL (or PL/pgSQL) functions from EdgeDB, because there is no way to _define_ or manage them. The only place that is allowed to do this is the standard library (and, in the near future, extensions).
We realize that the database must be extensible and flexible, so non-EdgeQL UDF will become a reality (and if things work out the way we hope they will, they'll be amazing and far beyond what you can do with plpgsql).
We realize that the database must be extensible and flexible, so non-EdgeQL UDF will become a reality (and if things work out the way we hope they will, they'll be amazing and far beyond what you can do with plpgsql).