Cron removes dblog watchdog I set the cron to run every day.

I want to prevent the cron from deleting some of the watchdog table content.

But i didn't find a way to do it, i still want the cron to run for the search index.

How can i prevent the cron from deleting dblog (watchdog) informations only ?
What you can do easily is configure how many records are kept at /admin/config/development/logging, you can set it up to 1 million, which is quite a lot.

To disable it completely (which I would not recommend), you could use a module like ultimate cron, which allows to control how often the cron job of each module is called separately.