rp_renping的专栏

Note: The UNION operator selects only distinct values by default. To allow duplicate values, use UNION ALL. Using the [charlist] Wildcard Now we want to select the persons with a last name that st...

分页查询还有一个很明显的特点，就是处理的页数越小，效率就越高，越到后面，查询速度越慢。 type 1: 大多数情况下优于type2 select * from ( select temp.*, ROWNUM rn from (select * from tablename) temp where ROWNUM = startRow type...

常规路径导出： exp username/pass@servicename file=/filename.dmp buffer=20480000 直接路径导出方式： exp username/pass@servicename file=/filename.dmp recordlength=65535 direct=y