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  1. MariaDB Server
  2. MDEV-15163

Massive performance impact after PTI fix 2

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      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

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              • Assignee:
                axel Axel Schwenke
                Reporter:
                falcoris Jean-Marc Messina
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                • Created:
                  Updated: