oracle中truncate、drop等ddl语句都产生redo 和undo信息sys@ORCL> select m.value,s.name from v$mystat m join v$statname s on m.statistic#=s.statistic# where s.name in ('undo change vector size', 'redo size'); VALUE NAME---------- --------------------------------------------------...【阅读全文】
#进行update操作:sys@ORCL> update hn.emp set sal=3000 where empno=7902;sys@ORCL> select b.name,a.value 2 from v$mystat a,v$statname b 3 where a.statistic#=b.statistic# and b.name in ('redo size','undo change vector size');NAME &nbs...【阅读全文】
v$database:数据库的信息,如数据库名,创建时间等。v$instance 实例信息,如实例名,启动时间。v$parameter 参数信息,select * from v$parameter where name like '%name' ----> show parameter name(sqlplus中执行)v$process 运行的进程的信息,如PID,SPID,以及进程的名字,如SMON,PMON在UNIX的进程名...【阅读全文】
Oracle数据库和监听随LINUX系统启动1.确保“/etc/oratab”文件内容的正确性有则修改,无则创建“/etc/oratab”文件。该文件的功能是控制Oracle的启动(dbstart)和关闭脚本(dbshut)是否可用。# vi /etc/oratabHS2008(实例名):/oracle/app/oracle/product/10.2.0/db_1:Y只有当尾部为“Y”...【阅读全文】
1:使用vmstat和top查看系统cpu,io,内存使用情况2:查看当前状态下存在的等待事件select sid,event,p1,p2,seconds_in_wait from v$session_wait where event not like '%SQL%' and event not like 'rdbms%' and event not like '%message%' and event not like '%Streams AQ%' AND EVENT NOT LIKE '%slave%' order by e...【阅读全文】
今天重读ORACLE官方文档《concepts》,读到schema的基本概念,对它的理解更进一层,官方文档中关于schema是这样解释的: “A schema is a collection of database objects. A schema is owned by a database user and has the same name as that user. Schema objects are the logical structures that directly r...【阅读全文】
最近在使用impdp导入数据的时候,因源库gbk与目标库utf8的字符集不一样,造成导入时目标库中表的字段长度不够。报错信息如下:点击(此处)折叠或打开ORA-02374: conversion error loading table "HN_CM_IRMS_35_TNMS"."PTN_NE_TO_SERVICE"ORA-12899: value too large for colu...【阅读全文】