timescaledb delete from compressed hypertable with segmentby

delete_by_segmentby.sql

CREATE OR REPLACE FUNCTION delete_segmentby(_tbl regclass, _col varchar, _id anyelement, OUT result integer)
    LANGUAGE plpgsql AS
$$
DECLARE
	_schema varchar := (SELECT nspname
		FROM pg_catalog.pg_class AS c
		JOIN pg_catalog.pg_namespace AS ns
		  ON c.relnamespace = ns.oid
		WHERE c.oid = _tbl);
	_table_name varchar := (
		SELECT relname
		FROM pg_catalog.pg_class
		WHERE oid = _tbl);
	_htc varchar := (
		select '_timescaledb_internal.' || table_name 
		from _timescaledb_catalog.hypertable 
		where id = (
			select compressed_hypertable_id from _timescaledb_catalog.hypertable where schema_name = _schema and table_name = _table_name)
		);
	count int;
	_hypertable_id int;
	_r record;
BEGIN
	raise notice 'table: %', _tbl;
	raise notice 'table_name: %', _table_name;
	raise notice 'schema: %', _schema;
	raise notice 'compressed hypertable: %', _htc;
	EXECUTE format('delete FROM %s WHERE %s = %s', _htc, quote_ident(_col), quote_literal(_id));
	GET DIAGNOSTICS result = ROW_COUNT;
	raise notice 'deleted on compressed %: %', _htc, result;
	select id into _hypertable_id from _timescaledb_catalog.hypertable where schema_name = _schema and table_name = _table_name;
	FOR _r IN select * from _timescaledb_catalog.chunk where hypertable_id = _hypertable_id and compressed_chunk_id is null LOOP
		EXECUTE format('delete FROM ONLY %s WHERE %s = %s', _r.schema_name || '.' || _r.table_name, quote_ident(_col), quote_literal(_id));
		GET DIAGNOSTICS count = ROW_COUNT;
		raise notice 'delete on chunk: % chunk: %', count, to_jsonb(_r);
		result := result + count;
	end loop;
END
$$;