SQL> select count(*)  from  sms.sms_asdfasdf_subscribe_log_chinamobile;

  COUNT(*)
----------
      4674

SQL> select count(*) from sms.sms_area_mobile_chinamobile;

  COUNT(*)
----------
     18040




这条语句还能优化吗?

select count(mobile) from sms.sms_asdfasdf_subscribe_log_chinamobile a, sms.sms_area_mobile_chinamobile b where b.mobile_s<=a.mobile and a.mobile<=b.mobile_e  and subscribe_flag='0' and log_date>='20080401' and log_date<='20080418235959'  ;

COUNT(MOBILE)
-------------
         2183

Elapsed: 00:00:20.61

Execution Plan
----------------------------------------------------------
   0      SELECT STATEMENT Optimizer=CHOOSE
   1    0   SORT (AGGREGATE)
   2    1     NESTED LOOPS
   3    2       TABLE ACCESS (FULL) OF 'SMS_asdfasdf_SUBSCRIBE_LOG_chinamobile'
   4    2       INDEX (RANGE SCAN) OF 'IND_AREA_MOBILE_chinamobile' (NON-UNIQUE
          )





Statistics
----------------------------------------------------------
          0  recursive calls
          0  db block gets
     119363  consistent gets
          0  physical reads
          0  redo size
        524  bytes sent via SQL*Net to client
        656  bytes received via SQL*Net from client
          2  SQL*Net roundtrips to/from client
          0  sorts (memory)
          0  sorts (disk)
          1  rows processed

[ 本帖最后由 lijiebin 于 2008-4-21 09:31 编辑 ]