valor máximo de energia gasta numa determinada data

olá a todos, tenho uma tabela que recebe o valor da energia gasta de uma linha de produção, este valor é actualizado segundo a segundo, os campos sao LineNumber(Number), DateTime(timestamp ) e Energy(Number).

com este SQL:

select a."DateTime", max(a."Energy") as LINE_ENERGY
from z_opc_tags a
where a."Line_Number" = '32027'
and trunc(a."DateTime") = trunc(to_date('20.07.2009','dd.mm.YYYY HH24:MI:SS'))
group by a."DateTime";

• consigo esta listagem, mas nao é isto que pretendo,o que pretendo era o valor máximo que neste caso seria 6340, neste registo 09.07.20 22:00:01,000000000 6340
• estou a tentar primeiro para um dia, porque o objectivo final é obter o valor máximo de vários dias.

-obrigado pela ajuda desde já

09.07.20 22:00:01,000000000 6340

09.07.20 21:59:05,000000000 6340

09.07.20 21:58:01,000000000 6340

09.07.20 21:57:00,000000000 6340

09.07.20 21:56:01,000000000 6340

09.07.20 21:55:00,000000000 6340

09.07.20 21:54:00,000000000 6340

09.07.20 21:53:00,000000000 6340

09.07.20 21:52:00,000000000 6340

09.07.20 21:51:00,000000000 6340

09.07.20 21:50:00,000000000 6340

09.07.20 21:49:00,000000000 6340

09.07.20 21:48:00,000000000 6340

09.07.20 21:47:00,000000000 6340

09.07.20 21:46:00,000000000 6340

09.07.20 21:45:00,000000000 6340

09.07.20 21:44:00,000000000 6340

09.07.20 21:43:00,000000000 6340

09.07.20 21:42:00,000000000 6340

09.07.20 21:41:00,000000000 6340

09.07.20 21:40:00,000000000 6340

09.07.20 21:39:00,000000000 6340

09.07.20 21:38:05,000000000 6340

09.07.20 21:37:00,000000000 6340

09.07.20 21:36:00,000000000 6340

09.07.20 21:35:00,000000000 6320

09.07.20 21:34:00,000000000 6320

09.07.20 21:33:01,000000000 6320

09.07.20 21:32:05,000000000 6320

09.07.20 21:31:01,000000000 6320

09.07.20 21:30:00,000000000 6320

09.07.20 21:29:01,000000000 6320

09.07.20 21:28:00,000000000 6320

09.07.20 21:27:00,000000000 6320

09.07.20 21:26:00,000000000 6320

09.07.20 21:25:01,000000000 6320

09.07.20 21:24:00,000000000 6320

09.07.20 21:23:00,000000000 6320

09.07.20 21:22:00,000000000 6320

09.07.20 21:21:00,000000000 6320

09.07.20 21:20:00,000000000 6320

09.07.20 21:18:01,000000000 6320

09.07.20 21:17:00,000000000 6320

09.07.20 21:16:00,000000000 6320

09.07.20 21:15:00,000000000 6320

09.07.20 21:13:59,000000000 6320

09.07.20 21:13:00,000000000 6320

09.07.20 21:12:05,000000000 6320

09.07.20 21:11:00,000000000 6320

09.07.20 21:10:05,000000000 6320

09.07.20 21:09:00,000000000 6320

09.07.20 21:08:01,000000000 6300

09.07.20 21:07:01,000000000 6300

09.07.20 21:06:01,000000000 6300

09.07.20 21:05:01,000000000 6300

09.07.20 21:04:01,000000000 6300

09.07.20 21:03:00,000000000 6300

09.07.20 21:02:01,000000000 6300

09.07.20 21:01:01,000000000 6300

09.07.20 21:00:01,000000000 6300

09.07.20 20:59:00,000000000 6300

09.07.20 20:58:01,000000000 6300

09.07.20 20:57:01,000000000 6300

09.07.20 20:56:01,000000000 6300

Abraço

matinha