小编Elv*_*Lou的帖子

我有一个约100k记录的表,我想删除一些行,问题是该DELETE语句运行速度非常慢 - 它没有在30分钟内完成.但该select声明在1秒内回归.

该SELECT声明如下:

select * from daily_au_by_service_summary 
    where summary_ts >= to_date('09-04-2012','dd-mm-yyyy') 
    order by summary_ts desc;

并DELETE声明如下:

delete from daily_au_by_service_summary 
    where summary_ts > to_date('09-04-2012','dd-mm-yyyy');

此表的唯一索引位于summary_ts.

可能是什么原因？

编辑:该表被许多会话锁定:

SESSION_ID ORACLE_USERNAME                OS_USER_NAME                   OBJECT OWNER                   OBJECT_NAME                                                                                                                      OBJECT_TYPE         LOCKED_MODE
---------- ------------------------------ ------------------------------ ------------------------------ -------------------------------------------------------------------------------------------------------------------------------- ------------------- -----------
       213 T03RPT                         elou                           T03RPT                         DAILY_AU_BY_SERVICE_SUMMARY                                                                                                      TABLE                         3 
       203 T03RPT                         elou                           T03RPT                         DAILY_AU_BY_SERVICE_SUMMARY                                                                                                      TABLE                         3 
       202 T03RPT                         elou                           T03RPT                         DAILY_AU_BY_SERVICE_SUMMARY                                                                                                      TABLE                         3 
       190 T03RPT                         elou                           T03RPT                         DAILY_AU_BY_SERVICE_SUMMARY                                                                                                      TABLE                         3 …