Please ask help on the forums - Migrating and Upgrading to Joomla! 3.x. This repository concerns in first Place Joomla coding. For this Reason closing this Issue, thanks.

Set to "closed" on behalf of @franz-wohlkoenig by The JTracker Application at issues.joomla.org/joomla-cms/19188

This issue has nothing to do with upgrading Joomla.
It has to do with Joomla 3.8 being slower on large sites than 3.7 was, possibly due to the use of DISTINCT in components\com_content\models\articles.php

Given the initial issue report and the very vague "possibly due to the use of..." comment, right now there isn't really much that can be done to investigate or confirm a bug report, let alone fix it. Without good information on how to create an environment where the issue can be reproduced and what the symptoms of the issue are, there isn't anything we can do.

Sorry, but "after upgrade my site is slower" just isn't a detailed enough report to really say anything but what the initial response you got was.

Not my site. Just a bystander. I'll try to be a little less vague.
DISTINCT can be very slow. It was added to articles.php in 3.8.0
Is it required? Can it be done differently? or simply removed?

Thread Created on Joomla.org, Thanks a lot ! my previous thread was not in the correct category,

Btw can remove too Distinct ? so i can do a retry to upgrade.

Thanks,

f.