oracle 有7张表连接查询，选择一个时间区间来查询都要3分钟，实在太慢了

Question

大家有没有什么解决的办法
这是from后面的语句，把原来的<=都替换为between了，而且时间都有索引，只不过不是函数索引
FROM t1（表里有700w条数据） a
LEFT JOIN t2 b
ON a.po_id = b.id
AND b.is_deleted='0'
LEFT JOIN t3(表里有300w条数据) c
ON a.order_id = c.id
AND c.is_deleted='0'
LEFT JOIN t4（300w条数据） t
ON a.business_id = t.id
AND t.is_deleted ='0'
LEFT t5（120w条数据） n
ON t.fin_card_id = n.id
AND n.is_deleted ='0'
LEFT JOIN t6（100w条数据） g
ON a.GROUP_NUM = g.GROUP_NUM
AND g.is_deleted='0'
LEFT JOIN t7 d
ON a.fee_item = d.code
AND d.type = 'COST_TYPE'
AND d.is_deleted ='0'
WHERE a.CP_TYPE = 'Payment'
--AND instr(lower(a.GROUP_NUM), lower('GH')) > 0
AND a.COMPANY_ID ='0E277EEBD52B5AC0E0532429030A7194'
AND a.STATUS IN ('BeConfirm', 'Confirmed', 'ToFinance', 'Transfer')
--AND (c.START_TIME >= to_date('2016-07-01','yyyy-mm-dd')
--OR g.DEPARTURE_DATE >= to_date('2016-07-01','yyyy-mm-dd'))
--AND (c.START_TIME <to_date('2016-07-22','yyyy-MM-dd')+1
--OR g.DEPARTURE_DATE <to_date('2016-07-22','yyyy-MM-dd')+1)
and ((c.START_TIME between to_date('2015-07-01','yyyy-mm-dd') and to_date('2015-07-25','yyyy-MM-dd')+1) or (g.DEPARTURE_DATE between to_date('2015-07-01','yyyy-mm-dd') and to_date('2015-07-25','yyyy-MM-dd')+1))
AND a.is_deleted = '0'
ORDER BY a.GROUP_NUM,
c.ORDER_CODE,
c.START_TIME,
c.id DESC;

Answer 1

而且很多都不能走索引，很多条件逗得用模糊查询，除了状态啊，时间啊