Hi! >>>>> "MARK" == MARK CALLAGHAN <[email protected]> writes:
MARK> What are the difference between logical and physical IO? I assume you MARK> are using Oracle's terminology where a logical IO means that a page MARK> was read from the InnoDB buffer cache. MARK> 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 I assume it's number of IO from that comes from the page cache (not really an IO) and the number of IO that comes from doing a read() call. I will know more when I have looked at the patch later this week... Regards, Monty _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
