Mysql status variables caveats

While setting up Zenoss and reading Mysql documentation about status variables I learned:

  • All select_* variables ("Select statistics" graph in Zenoss) are actually about joins, not (all) selects. This also explains why there is no clear relation to com_select (which shows the amount of selects). ("Command statistics:selects" graph in Zenoss)
  • Com_select does not denote all incoming select commands. If you have a hit on your query cache, com_select is not incremented. So I thought we were doing less qps while in fact we were just getting more cache hits. Qcache_hits gets incremented on cache hits (but is not monitored by Zenoss)

Trackback URL for this post:

http://dieter.plaetinck.be/trackback/67
Submitted by Dieter_be on Sat, 06/06/2009 - 11:33. categories [ ]

irc and mail - dont publish

JPEC on freenode.net #archlinux-fr

you published it yourself.

you published it yourself. gonna leave it, it's too funny :)

Post new comment

The content of this field is kept private and will not be shown publicly.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Allowed HTML tags: <a> <em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd>
  • Lines and paragraphs break automatically.
  • You can enable syntax highlighting of source code with the following tags: <code>, <blockcode>. Beside the tag style "<foo>" it is also possible to use "[foo]". PHP source code can also be enclosed in <?php ... ?> or <% ... %>.

More information about formatting options

CAPTCHA
This question is for testing whether you are a human visitor and to prevent automated spam submissions.
Security question, designed to stop automated spam bots