union 与union all
union多个子查询结果集的集合,做去重处理。union all多个子查询结果集的集合,不做去重处理。SQL> create table tab1 as select * from user_objects;Table created.SQL> create table tab2 as select * from user_objects;Table created.SQL>set autot traceonly;select * from tab1 union select * from tab2;Execution Plan----------------------------------------------------------Plan hash value: 1398582079[@more@]------------------------------------------------------------------------------------| Id | Ope
ORA-00600错误的trouble shooting
ORA-00600错误,同ORA-7445错误一样,属于Oracle的内部错误,由kernel code 中报出,该错误不一定是Oracle的bug,也可能是操作系统、资源泄漏、硬件故障等等外部因素引起的。当00600错误发生时,会有一串参数带出,第一个参数标识了该错误是有那部分kernel code抛出的,其余参数是一些特性参数或内部变量,第一个参数可能是数字也可能是字符串。当抛出00600异常时,会把异常信息写入到alert.log日志中,并且会在USER_DUMP_DEST或者BACKGROUND_DUMP_DEST下产生trace文件。这个trace文件包含了,kernel如何抛出00600错误的一些非常重要的信息
expdp与ORA-39147异常
今天发现crontab中一个数据泵导出任务出现异常,错误信息如下。[oracle@w1]$ /apps/oracle/admin/msh/expdp_tb_affirm_weather.shExport: Release 10.2.0.4.0 - 64bit Production on Thursday, 27 November, 2009 18:01:51Copyright (c) 2003, 2007, Oracle. All rights reserved.Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit ProductionWith the Partitioning, Real Application Clusters, Data Mining and Real Application Testing optionsORA-31626: job does not existORA-31637: cannot creat