Uploaded image for project: 'MariaDB Server'
  1. MariaDB Server
  2. MDEV-15163

Massive performance impact after PTI fix 2

    XMLWordPrintable

Details

    Description

      I had already opened an issue that got closed legitimately : https://jira.mariadb.org/browse/MDEV-15072

      I have more elements but it doesn't seem that i can reopen the ticket so i'm posting a new one here.

      Is there a way to reopen it ?

      In case it's impossible, here are the elements :

      Hello

      I have just applied the PTI patch on the OS and it is causing a massive difference in the execution time of a specific query.

      Disabling and reenabling PTI enables me to reproduce the difference at will :

      PTI disabled : 7s
      PTI enabled : 87s

      The query :

      SELECT * FROM `test` as b1 WHERE b1.`dateFin` > '2018-01-24' AND NOT EXISTS (SELECT 1 FROM `test` as b2 WHERE b2.`ip` = b1.`ip` AND b2.`dateFin` > b1.`dateFin`);
      

      Explain doesn't show any difference with and without KPTI fix.

      Please find attached the table to reproduce the issue

      Attachments

        1. test.sql.gz
          43 kB
          Jean-Marc Messina

        Issue Links

          Activity

            People

              axel Axel Schwenke
              falcoris Jean-Marc Messina
              Votes:
              0 Vote for this issue
              Watchers:
              4 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved:

                Git Integration

                  Error rendering 'com.xiplink.jira.git.jira_git_plugin:git-issue-webpanel'. Please contact your Jira administrators.