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 <jiangchengyao@gmail.com> 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
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