看到叶金荣的一篇关于mysql分页的文章,结合雅虎之前发的一篇PDF 谈谈自己的看法
在叶子的文章里谈到了使用inner join 从而减少了对page的扫描也就是减少了所谓的回表 例如：
SELECT * FROM `t1` INNER JOIN ( SELECT id FROM `t1`ORDER BY id DESC LIMIT 935500,10) t2 USING (id)
通过直接对id的操作 而不是整张表的扫描 通过id 的join 抓出符合条件id 然后通过ID 再去做数据的抓取。这样就避免了对不需要的页面的扫描。
不过这样也不是最佳的方法 还可以通过对[……]
Reference Oracle AWR. These two was developed by python and perl.
Both of these are following data collection method.
Use these tools can help quick identify problem.
MyAWR v2 –collection of mysql and os information
很久之前看过这个帖子,当时没有细究,这几天看了下mysql相关的internal 突然想起这个问题,跟三四个朋友讨论了下 想把这个问题展开讲一讲。
源帖子内容见：https://community.oracle.com/thread/1087650?start=0&tstart=0
这个帖子的内容为一个老外问oracle如何避免partial write的,也就是大家所说的半个IO问题,IO 在写到一半的时候发生断裂,（瞬间断线,瞬间crash瞬间存储或者机器故障等） 虽然这个情况极少发生,但是在非常规恢复的时候也是经常遇到的,例如某个block内部出现不一致,也就是我们所谓的逻辑[……]
戴尔近日推出了旗下的13G服务器,其主力机型为R730xd,包含了诸多的特性,为其成为主流db server以及规模存储集群打下了良好的基础。
具体参考：http://www.storagereview.com/dell_poweredge_13g_r730xd_review
http://www.storagereview.com/dell_poweredge_gen13_servers_released
https://www.youtube.com/watch?v=YSGzB7umHa0
具体增强为：
1.CPU 为intel haswall最新架构,减少了功能[……]
You can download webm from github: https://github.com/ylouis83/webm
webm: mysql web key performance monitor
webm is a tool that display key value graph on website and webm was developed by javascript and mysqlmon ( mysql data collection tool wrote by AnySQL)
Environment need:
Linux vers[……]
Webm_v2 was add oracle and mongodb monitor module
webm was agent uploaded mode to save statistics
we use mysql database as monitor server
we already design tables to store these data (consider for future analysis)
you can download from github : https://github.com/ylouis83/webm[……]
history of myawr:
————————–
v1: create by noodba
mysql load information and system information
v2: create by louis liu
myawr_v2 add :
1 more os information module. 2 multiple instance support (extend table by db_port) 3 modified[......]
Copy table between different hbase clusters – Version 0.96.2-hadoop2
Create test table and initial some records.
$hbase shell 2014-12-19 15:01:36,085 INFO [main] Configuration.deprecation: hadoop.native.lib is deprecated. Instead, use io.native.lib.available HBase Shell; enter 'help<[......]
演示一下12c中关于pdb的listener register,unregister问题
[oracle@db-42 ~]$ lsnrctl status listener1 LSNRCTL for Linux: Version 12.1.0.1.0 - Production on 09-AUG-2013 14:53:56 Copyright (c) 1991, 2013, Oracle. All rights reserved. Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=db-42)(PORT[......]
