<?xml version="1.0" encoding="utf-8"?>
<launchpad-bug id="639949">
  <date_last_updated>2010-11-23 20:21:32.900918+00:00</date_last_updated>
  <api_links>
    <bug_api_link>https://api.launchpad.net/1.0/bugs/639949</bug_api_link>
    <bug_owner_link>https://api.launchpad.net/1.0/~joce</bug_owner_link>
    <milestone_link></milestone_link>
    <linked_branches_collection_link>https://api.launchpad.net/1.0/bugs/639949/linked_branches</linked_branches_collection_link>
    <activity_link>https://api.launchpad.net/1.0/bugs/639949/activity</activity_link>
  </api_links>
  <bug_web_link>https://bugs.launchpad.net/bugs/639949</bug_web_link>
  <owner>jocelyn fournier</owner>
  <assignee></assignee>
  <milestone_title></milestone_title>
  <duplicate_link></duplicate_link>
  <duplicate_bug_id></duplicate_bug_id>
  <title>Non optimal index choice, depending on index creation order</title>
  <status>New</status>
  <importance>Undecided</importance>
  <created>2010-09-15 20:55:25.248384+00:00</created>
  <description>
<![CDATA[Hi,

There are several simple cases where MySQL optimiser doesn't select the right index. This entails strong performance issues, and force the developers to hack their applications, using USE INDEX (when it's possible...)

This wrong optimizer behaviour is explained in detail here : http://bugs.mysql.com/bug.php?id=36817

The bugs also occurs both in MariaDB 5.1 & 5.2.

Since this bug is around for more than 2 years now, I really hope it could be fixed really soon in MariaDB.

Thanks and regards,
  Jocelyn Fournier]]>  </description>
  <activities>
    <activity datechanged="2010-09-15T20:55:25.248384+00:00">
      <oldvalue>
<![CDATA[]]>      </oldvalue>
      <newvalue>
<![CDATA[]]>      </newvalue>
      <whatchanged>bug</whatchanged>
      <person>jocelyn fournier</person>
      <message>added bug</message>
    </activity>
    <activity datechanged="2010-10-19T07:29:25.015143+00:00">
      <oldvalue>
<![CDATA[]]>      </oldvalue>
      <newvalue>
<![CDATA[maria/5.1]]>      </newvalue>
      <whatchanged>nominated for series</whatchanged>
      <person>jocelyn fournier</person>
      <message></message>
    </activity>
    <activity datechanged="2010-10-19T07:29:25.015143+00:00">
      <oldvalue>
<![CDATA[]]>      </oldvalue>
      <newvalue>
<![CDATA[maria/5.2]]>      </newvalue>
      <whatchanged>nominated for series</whatchanged>
      <person>jocelyn fournier</person>
      <message></message>
    </activity>
    <activity datechanged="2010-10-19T07:29:25.015143+00:00">
      <oldvalue>
<![CDATA[]]>      </oldvalue>
      <newvalue>
<![CDATA[maria/5.3]]>      </newvalue>
      <whatchanged>nominated for series</whatchanged>
      <person>jocelyn fournier</person>
      <message></message>
    </activity>
    <activity datechanged="2010-11-23T20:21:32.463880+00:00">
      <oldvalue>
<![CDATA[]]>      </oldvalue>
      <newvalue>
<![CDATA[]]>      </newvalue>
      <whatchanged>bug</whatchanged>
      <person>Alexey Kopytov</person>
      <message>added subscriber Alexey Kopytov</message>
    </activity>
  </activities>
</launchpad-bug>
