Yes, Logical IO means pages from buffer pool, physical IO means pages read from disk
2012-01-05 jiangchengyao 发件人：MARK CALLAGHAN 发送时间：2012-01-05 04:39 主题：Re: [Maria-developers] IO statistic in slow log 收件人：jiangchengyao 抄送：maria-developers What are the difference between logical and physical IO? I assume you are using Oracle's terminology where a logical IO means that a page was read from the InnoDB buffer cache. On Thu, Dec 29, 2011 at 6:41 PM, jiangchengyao <[email protected]> wrote: > Hi, all > > I write a patch to show physical & logical IO statistics in slow log. Now it > only support XtraDB storage engine, but it is easy to realize in other > engine. You may found it like this in slow log: > > # Time: 111227 16:29:54 > # User@Host: root[root] @ localhost [::1] > # Query_time: 0.310018 Lock_time: 0.203012 Rows_sent: 1 Rows_examined: > 30000 Logical_IO: 30145 Physical_IO: 50 > use tpcc; > SET timestamp=1324974594; > select count(1) from history; > > I think this feature is much helpful for DBA or Developer to know what the > real IO one SQL has. In addition, it is simple, only a few changes should be > made. > > The branch is: https://code.launchpad.net/~jiangchengyao/+junk/mariadb > > Regards, > David > > 2011-12-30 > ________________________________ > jiangchengyao > > _______________________________________________ > Mailing list: https://launchpad.net/~maria-developers > Post to : [email protected] > Unsubscribe : https://launchpad.net/~maria-developers > More help : https://help.launchpad.net/ListHelp > -- Mark Callaghan [email protected]
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