oracle support一次危机处理（之一）
天有不测风云，
IBM 的中端磁盘阵列这次又惹祸了。在微码升级的时候，
DS4800 发生故障。IBM工程师把阵列故障恢复后，拍拍屁股走人，留下了阵列上不一致的数据。
没办法，阵列上的数据又得我们来想办法抢救了。。。。
还好有oracle support的支持我们最终化解了这次危机。下文详细介绍了整个恢复的过程。
oracle工程师到达现场后，根据错误信息，
问题情况如下SR信息所示：（HP-UX PA-RISC (64-bit)+ORACLE 9.2.0.8.0.+filesystem+no archivelog mode+no backup)
** Customer's Management 24x7 contact name:***************
** Customer's Management 24x7 contact number: ****************
** Primary Customer contact name: *******************
** Current Customer 24x7 voice phone number: ********************
** Current Customer E-mail address: ********************
** Current Customer Pager/Fax number: *****************
### Characteristics of Problem ###
This is a critical production system
Database is down and will not start
Data corruption issue and media recovery failed to fix the problem
### Note:28814.1 did not help because: ###
It did not have the needed information.
### Other: Note:28814.1 did not help because: ###
Sys owned objects corrupted
### The corruption was detected on: ###
Data file.
### Other: The corruption was detected on: ###
system tablespace
### The corruption affected a segment of type: ###
Table.
### Other: The corruption affected a segment of type: ###
TRANSACTION MANAGED DATA BLOCK
### The affected segment belongs to: ###
Database Dictionary.
### Other: The affected segment belongs to: ###
Database dictionary
### What error(s) and message(s) are Oracle reporting? ###
09:52:24 SQL> recover database allow 1 corruption;
ORA-00283: recovery session canceled due to errors
ORA-10562: Error occurred while applying redo to data block (file# 1, block# 1490)
ORA-10564: tablespace SYSTEM
ORA-01110: data file 1: '/oradata/yincang/rlv_system'
ORA-10561: block type 'TRANSACTION MANAGED DATA BLOCK', data object# 201
ORA-00600:
相关文档：
select trunc(sysdate ,'yyyy') from dual --本年度第一天
select trunc(sysdate ,'mm') from dual --本月第一天
&nbs ......
查询星期几:
select to_char(sysdate,'day') from dual;
查询几号:
select to_char(sysdate,'dd') from dual;
查询小时数:
select to_char(sysdate,'hh24') from dual;
查询时间:
select to_char(sysdate,'hh24:mi:ss') from dual;
查询日期时间:
select to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') from dual;
查 ......
在
Oracle
数
据库
中，
主要有两种
日志
操作模式，分别为非归
档模式与归档模式。默认情况下，数据库
采
用的是非归档模式
。作为一个合格的数据库管
理
员，应当深入了解这两种日志操作模式的特点，并且在数据库建立时，选
择合适的操作模式。
笔者
今天就谈谈自己对这两种操作模式的理解，并且给出 ......
Update SQLS will lead dead lock exception. Because by default, it use optimistic lock but not pessimistic lock.
Below description is exceprted from the attachment(It exceeds my image that this blog can not upload the attachment,hehe)
Optimistic locking offers an elegant solution to the problems o ......
什么是水线(High Water Mark)?
----------------------------
所有的oracle段(segments，在此，为了理解方便，建议把segment作为表的一个同义词) 都有一个在段内容纳数据的上限，我们把这个上限称为"high water mark"或HWM。这个HWM是一个标记，用来说明已经有多少没有使用的数据块分配给这个segment。HWM通常增长的幅� ......
