rdbms

[12c new feature] 针对 pluggable database的操作

July 5, 2013 12c, oracle No comments

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 20[......]

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how to study oracle and some useful habits

July 4, 2013 advanced tech, oracle No comments

最近做的一次内部交流文档[……]

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[12c new feature] slow IO tracing by views

July 3, 2013 12c, oracle No comments

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
 -----------------------------------[......]

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[12c new feature] add column enhancement

June 27, 2013 12c, oracle 1 comment

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[......]

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Recent MySQL performance Test detial

June 14, 2013 MYSQL, performance 2 comments

最近team基于mysql的性能基准测试,包含多种场景[……]

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ASM memory fragment problem in 11gR2 RAC

June 7, 2013 oracle, RAC No comments

前天处理了一启RAC ASM 内存泄露问题,系统为公司最后一套RAC one node 版本为11.2.0.3

这套核心RAC one node系统出现大量 log file switch buffer busy waits等待,并伴随大量cursor: pin S wait on X re[……]

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MyAWR another mysql awr –That is Great !!

May 22, 2013 Architecture, MYSQL, performance No comments

MyAWR 开源了,第一版的reference 已经放出, tx to noodba

MyAWR_Reference_Guid
slideshare地址:MyAWR (awr of MySQL)
MyAWR template:MySQL WorkLoad Report[……]

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How to control CF calculation

May 14, 2013 Internals, oracle No comments

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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MySQL AWR – Myawr

May 6, 2013 Architecture, MYSQL, performance No comments

noodba同学写的基于mysql的 WORKLOAD REPOSITORY工具,目前还没有开源 非常的给力!!

主要思想为一台管理机器,集中了所有client端的数据,client 为mysql database 使用host_id来区分 如 host_id=1代表mysql databas[……]

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Optimizer in Oracle 11g by wwf.

April 11, 2013 11g, advanced tech, oracle No comments

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

[……]

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