CREATE OR REPLACE FUNCTION rep_delete_stamp() RETURNS trigger 
AS $$
DECLARE 
	pkns name[] := NULL;
	pkn name := NULL;
	pkv VARCHAR( 34 ) := NULL;
BEGIN
	pkns := rep_pkeys(TG_RELNAME);
	IF (array_upper(pkns,  1 ) =  1 ) THEN
		pkn := pkns[ 1 ];
		EXECUTE 'pkv = OLD.' || pkn; -- Ошибка!
                -- pkv := OLD.PK_COL_NAME; -- А так - работает.
	ELSE
		-- TODO: Compound key values.
	END IF;
	INSERT INTO rep_deletelog (tablename, pkname, pkvalue) 
	VALUES 	(TG_RELNAME, pkn, pkv);
	RETURN NULL;
END;
$$ LANGUAGE plpgsql;

CREATE TABLE rep_deletelog (
	uid SERIAL NOT NULL,
	tablename name NOT NULL,
	pkname name NULL,
	pkvalue VARCHAR( 34 ) NULL,
	ts TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
	PRIMARY KEY (uid)
);

CREATE OR REPLACE FUNCTION rep_delete_stamp() RETURNS trigger 
AS $$
DECLARE 
	pkn name := NULL;
	pkv VARCHAR( 34 ) := NULL;
	pkns name[] := NULL;
	query text;
BEGIN
	pkns := rep_pkeys(TG_RELNAME);
	IF (array_upper(pkns,  1 ) =  1 ) THEN
		pkn := pkns[ 1 ];
		pkns := NULL;
		SELECT OLD.* INTO TEMPORARY rep_tmp;
		query := 'INSERT INTO rep_deletelog (tablename, pkname, pkvalue) SELECT ''' || TG_RELNAME || ''', ''' || pkn || ''', ' || pkn || ' FROM rep_tmp;';
		EXECUTE query;
		DROP TABLE rep_tmp;
	ELSE
		-- TODO: Implement compound primary key support, as necessary.
		RAISE EXCEPTION 'The table % has compound primary key - not supported', TG_RELNAME;
	END IF;
	RETURN NULL;
END;
$$ LANGUAGE plpgsql;