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Some exadata disk tips

July 29, 2013 Exadata, oracle No comments Exadata

针对exadata最近频繁报出的IO error,做如下总结

data node alert

ORA-27603: 单元存储 I/O 错误, I/O 在磁盘 o/192.168.10.5/DATA_DM01_CD_08_dm01cel03 上失败, 偏移量 17331625984 (数据长度 253952) ORA-27626: Exadata 错误: 201 (Generic I/O error) WARNING: Read Failed. group:1 disk:32 AU:4132 offset:761856 size:253952 path:o/192.168.1[......]

MySQL InnoDB的一些非常规恢复

July 9, 2013 Internals, MYSQL 2 comments mysql

最近关于下厨房的数据恢复,讨论的很火热,乘机测试了把Percona Data Recovery Tool for InnoDB工具,并且事实证明这款工具对一些操作的恢复,还是比较困难的。

我们以一张小表为例做一个测试:

mysql> select * from  customer;
+-------------+----------+------------+-----------+-------------------+------------+--------+---------------------+---------------------+
| custome[......]Read more

[12c new feature] 针对 pluggable database的操作

July 5, 2013 12c, oracle No comments 12c new feature

1. create Pluggable database from NON_CDB database.

[oracle@db-42 ~]$ ora si 

SQL*Plus: Release 12.1.0.1.0 Production on Fri Jul 5 13:07:08 2013

Copyright (c) 1982, 2013, Oracle.  All rights reserved.


Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Pr[......]Read more

how to study oracle and some useful habits

July 4, 2013 advanced tech, oracle No comments training

最近做的一次内部交流文档[……]

YHD DBA官方BLOG上线

July 4, 2013 Architect No comments

www.yhddba.com (主站点)
www.yihaodiandba.com (备份站点会有一天的延迟)

同时开通访问,主要记录日常的一些问题处理,以及针对互联网的数据架构想法。[……]

[12c new feature] slow IO tracing by views

July 3, 2013 12c, oracle No comments 12c new feature

根据JL,Glen Fawcett 的文章 oracle 从12c开始提供了3个视图来探测慢速的IO

SQL> desc V$LGWRIO_OUTLIER;
 Name					   Null?    Type
 ----------------------------------------- -------- ----------------------------
 FUNCTION_NAME					    VARCHAR2(18)
 IO_SIZE					    NUMBER
 WAIT_EVENT					    VARCHAR2(64)
 FILE_NA[......]Read more

[12c new feature] add column enhancement

June 27, 2013 12c, oracle 1 comment 12c new feature

首先我们看一组测试数据库版本oracle 12c beta1

SQL> select count(*) from test;

  COUNT(*)
----------
    725888

SQL> set timing on;
SQL> alter table test add name varchar(20) default 'liu';

Table altered.

Elapsed: 00:00:00.02



Elapsed: 00:00:00.01
SQL>  alter table[......]Read more

Database-exporter release v1.0

June 21, 2013 Architect, software No comments database migrate

Database-exporter发布感谢wucharles,一个充满Geek精神的小伙。

1.supports export database from each other. (you need write driver by yourself,now support oracle and MySQL) 2.supported database: Oracle, MySQL.(from oracle to mysql or mysql to oracle) 3.supports multi source tables merged into one target ta[......]