Maclean Liu(刘相兵 发表于 2012-1-23 22:27:21

Oracle Disk I/O Internals

Oracle tuning used to be largely focused on tuning file I/O.  Now tuning is focused on wait events, many of which are file I/O related.  Lately the evolution of server hardware is again changing how we look at tuning our Oracle databases.  Some of these changes are:

1.
Spinning hard disks are obsolete, but refuse to die.

Hard disks should have gone away by now, but just when you think they are done for, they emerge faster with more space and lower cost.

2.
Solid State Disks have arrived.  

SSDs are now cost effective to implement even on low to midrange servers.  Although slower than memory, they are an order of magnitude faster than spinning disk.

3.
Memory costs are quickly dropping.

Having 4G of RAM was impressive only a few years ago.  Now midrange servers routinely have 24-32G RAM.  Today’s standard is a 64 bit OS.  All this memory reduces file I/O considerably, but not entirely.  The database still needs to get those changes on to a non-volatile memory, i.e. disk, SSD, etc.

4.
CPUs are becoming multi-core and more powerful.

With all that memory, you would think I/O would go away.  However, modern CPUs are pushing the bottleneck back to the I/O subsystem.

What this means to the DBA is that file I/O is still important and still a key part of getting your Oracle database to optimal performance.


zhuqibs 发表于 2012-2-11 14:05:15

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icnm 发表于 2012-6-13 09:55:16

看看，能否对新来的给点活动资金

1112061 发表于 2012-7-18 11:14:47

io的知识，要下来看看那

casper0511 发表于 2012-12-5 09:32:27


io的知识，要下来看看那

albert 发表于 2012-12-6 14:48:35

望文止渴啊，
真想下来看看

xin_chy 发表于 2012-12-9 23:05:04

文章不错，顶一个！

GavinGreen 发表于 2012-12-10 15:01:11

跟个贴呵呵

yslaoniu 发表于 2013-5-6 23:38:58

学习一下，多谢~~

clot09 发表于 2013-8-1 17:19:21

学习了～

xw721xw 发表于 2013-8-26 00:41:16

ziyoo0830 发表于 2013-11-14 08:39:26

下载，收藏。

jinyu 发表于 2014-7-15 15:48:21

看看,多谢楼主

justinleisure 发表于 2014-7-18 21:35:50

下载下来看看

liuyl_it 发表于 2020-9-26 20:56:15

的确是好资料！

aesthetik 发表于 2021-12-31 10:17:58

好资料！

aesthetik 发表于 2021-12-31 10:18:25

好资料！

aesthetik 发表于 2021-12-31 10:18:56

楼主威武

aesthetik 发表于 2021-12-31 10:20:06

文章不错，顶兵

aesthetik 发表于 2021-12-31 10:21:28

that's perfect documents,love you maclean
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