谁能帮我优化一下这个查询? 你的各个表的数据量,表字段的索引情况,等等一无所知,怎么帮你优化啊.你还是自己看explain plan. 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 看不出什么,效率不应该不受这句SQL本身的影响 建立以下索引:vhpcestatus表 time_stamp字段sfc_batch表 time_stamp字段VHWKCSTATUS表 (time_stamp,object_id)字段上建立复合索引c_work_center表 id字段然后修改语句SELECT /*+ ordered*/ PCETIME.PCE_ID ID, PCETIME.LASTTIME KEEPTIME, wkc.id WKCID FROM (SELECT /*+ ordered*/ DISTINCT v.object_id PCE_ID, MAX(v.time_stamp) max_time_stamp, MIN((SYSDATE - t.START_TIME) * 24 * 60) LASTTIME FROM vhpcestatus v, sfc_batch t, VHWKCSTATUS w, c_work_center wkc WHERE v.time_stamp = t.time_stamp AND w.time_stamp = v.time_stamp --and v.object_id = 414468421 AND wkc.id = w.object_id GROUP BY v.object_id) PCETIME, VHWKCSTATUS w, c_work_center wkc WHERE w.time_stamp = PCETIME.max_time_stamp AND wkc.id = w.object_id只是粗略而且大概的估计了一下,呵呵 备份system表空间的问题 请教大虾数据库间表同步? 求教,做一个财务借贷程序,为零的值显示NULL ,(也就是不显示) 按单位产生ID的问题,在线等! 这种查询怎么写?高手救命!急急急 统计里面根据某一字段去除相通项 execute immediate 和事务的问题 ~~~~急!!~~~请高手给个解决方法,谢谢 急问:9i安装总出错,怎么办?? 存储过程中动态游标如何用?我这个存储过程不能通过,请各位帮忙看看吧。 请教:从MSSQL转到ORACLE的问题? ORACLE是垃圾,不折不扣的垃圾
vhpcestatus表 time_stamp字段
sfc_batch表 time_stamp字段
VHWKCSTATUS表 (time_stamp,object_id)字段上建立复合索引
c_work_center表 id字段然后修改语句
SELECT /*+ ordered*/ PCETIME.PCE_ID ID, PCETIME.LASTTIME KEEPTIME, wkc.id WKCID
FROM (SELECT /*+ ordered*/ DISTINCT v.object_id PCE_ID,
MAX(v.time_stamp) max_time_stamp,
MIN((SYSDATE - t.START_TIME) * 24 * 60) LASTTIME
FROM vhpcestatus v, sfc_batch t, VHWKCSTATUS w, c_work_center wkc
WHERE v.time_stamp = t.time_stamp
AND w.time_stamp = v.time_stamp
--and v.object_id = 414468421
AND wkc.id = w.object_id
GROUP BY v.object_id) PCETIME,
VHWKCSTATUS w,
c_work_center wkc
WHERE w.time_stamp = PCETIME.max_time_stamp
AND wkc.id = w.object_id只是粗略而且大概的估计了一下,呵呵