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How to control CF calculation

Posted by admin on May 14th, 2013

根据Richard Foote的文章,做了如下验证:

RefClustering Factor Calculation Improvement and provide some control over DBMS_STATS index clustering factor computat[......]

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Optimizer in Oracle 11g by wwf.

Posted by admin on April 11th, 2013

By wwf from ebay COC about Optimizer in Oracle 11g.

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Update exadata flash disk firmware due to poor performance on X2-2

Posted by admin on March 14th, 2013

ASR XD报警抛出如下错误

"
dm01cel02: Hardware Error has been detected in the Flash Logs on the Cell Node
dm01cel02: Please open up a Service Request[......]

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Active dataguard tips

Posted by admin on January 23rd, 2013

11g ADG 给了大家更多的灾备选择,包括之前美国飓风,给了ADG大放光彩的机会,但是ADG并没有想象中的那么完美,以下是最近的一个CASE,具体过程不详写了,目前这个case还在跟进中,记录之:

[oracle@dcb-srv-0174 trace]$ cat itemstd02_ora_[......]

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Scripts: Monitor Tablespace space growth

Posted by admin on January 10th, 2013

这个脚本可以监控tablespace 空间增长趋势,并且邮件通知到相关domain– 根据TOAD SPACE MANAGEMENT 修改

创建schema,tablespace,table:

create tablespace toad '+ARCH/data/tbs_ts[......]

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Block split and entry reorder

Posted by admin on December 12th, 2012

今天跟研发的同学讨论到了这个问题,index block split过程中涉及到的重新排序问题.

SQL> create table idx_split (a number, b varchar2(1446), c date);   
 
Table created
 

SQ[......]

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Scripts: dbms_backup_restore modify dbid and db_name

Posted by admin on December 5th, 2012

Scripts:dbms_backup_restore_dbid

eg:

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Par[......]

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Oracle Bind Graduation 测试

Posted by admin on November 28th, 2012

最近team 讨论 Bind Graduation 比较激烈,详细可以见上一篇文章,基于Bind Graduation 做了以下测试:

主要目的:

测试基于OCI JDBC 等接口的 Bind Graduation行为.针对目前Bind Graduation的行为,以及11.2.0.[......]

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Can not purge obsolete cursor in 11.2.0.3

Posted by admin on November 28th, 2012

11.2.0.3中Oracle引入了_cursor_obsolete_threshold隐藏参数,默认为100,表示一个parent cursor最多可以有100个child cursor;如果SQL需要第101个child cursor,则将该parent cursor and its 100 c[......]

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[转] ASM Handling Block Corruptions

Posted by admin on November 25th, 2012

Some excellent experiment From Honcho

为了保护disks 上的数据,Oracle ASM 对disk groups 有3种冗余方式:
(1)external redundancy 表示Oracle不帮你管理镜像,功能由外部存储系统实现,比如通过RAID技[......]

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