8.88. registry_get_timestamp(text, timestamp without time zone)

    DECLARE
    	p_key		alias for $1;
    	p_default	alias for $2;
    	v_value		timestamp;
    BEGIN
    	select reg_timestamp into v_value from sl_registry
    			where reg_key = p_key;
    	if not found then 
    		v_value = p_default;
    		if p_default notnull then
    			perform registry_set_timestamp(p_key, p_default);
    		end if;
    	else
    		if v_value is null then
    			raise exception 'Slony-I: registry key % is not an timestamp value',
    					p_key;
    		end if;
    	end if;
    	return v_value;
    END;