CREATE OR REPLACE FUNCTION get_node_childs(int4, int4, int4)
RETURNS TEXT AS '
DECLARE

	v_node_id ALIAS FOR $1;
	v_level_counter ALIAS FOR $2;
	v_auser_id ALIAS FOR $3;
	v_childs integer[] := \'{}\';

	node_rights int4;

BEGIN

	node_rights := get_rights_to_node(v_node_id, v_auser_id);

	IF node_rights & 1 THEN
		v_childs := get_node_childs_int(v_node_id, node_rights, v_level_counter, v_auser_id);
	END IF;

    RETURN array_to_string(v_childs, \',\');

END;
'
 LANGUAGE plpgsql
IMMUTABLE
RETURNS NULL ON NULL INPUT;


CREATE OR REPLACE FUNCTION get_node_childs_int(int4, int4, int4, int4)
RETURNS integer[] AS '
DECLARE

	v_node_id ALIAS FOR $1;
	v_parent_rights ALIAS FOR $2;
	v_level_counter ALIAS FOR $3;
	v_auser_id ALIAS FOR $4;

	v_childs integer[] := \'{}\';

	level_counter int4;

	vo_full_rights int4;
	parent_rights int4;
	node_info RECORD;

BEGIN

	level_counter := v_level_counter - 1;

	FOR node_info IN
		SELECT
			node.node_id,
			node.irf,
			node.owner,
			COALESCE(BIT_OR(acl.rights), 0) AS rights
		FROM node
		LEFT JOIN acl
			ON
				node.node_id = acl.node_id
			AND
				(
					acl.auser_id = v_auser_id
					OR
					acl.auser_id IN (SELECT parent_id FROM auser_to_auser WHERE auser_id = v_auser_id)
				)
		WHERE
			node.parent_id = v_node_id
		GROUP BY
			node.node_id,
			node.irf,
			node.owner
	LOOP

		IF node_info.irf <> 0 THEN
			parent_rights := v_parent_rights;
		ELSE
			parent_rights := 0;
		END IF;

		IF node_info.owner = v_auser_id OR v_auser_id = 3 THEN
			vo_full_rights := 63;
		ELSE
			vo_full_rights := (node_info.rights | (node_info.irf & parent_rights)) + 0;
		END IF;

		IF vo_full_rights <> 0 AND v_level_counter > 0 THEN
			v_childs := array_cat(v_childs, get_node_childs_int(node_info.node_id, vo_full_rights, level_counter, v_auser_id));
		END IF;

		IF vo_full_rights <> 0 THEN
			v_childs := array_append(v_childs, node_info.node_id);
		END IF;

    END LOOP;

    RETURN v_childs;

END;
'
 LANGUAGE plpgsql
IMMUTABLE
RETURNS NULL ON NULL INPUT;

SELECT * from get_node_childs( 117 ,  1 ,  3 );

SELECT * FROM node WHERE node_id IN(
	SELECT * from get_node_childs( 117 ,  1 ,  3 )
);

row number - 1  is out of range  0 ..- 1 
Total query runtime:  203  ms.
Data retrieval runtime:  47  ms.
 0  rows retrieved.