General help

Hello,
We are going to migrate our moodle 2.6 to moodle 2.8 in a week (we already did it on our test platform). I'm taking a special care to the new logging system.
I enabled the External database log feature (I created the external database before). Everything works well. Although, I have some questions about how it works, I couldn't find an answer yet.

I have 2 different logs :
- Standard log (Logs, Live logs, Activity report, Course participation, Statistics)
- External database log (Logs, Live logs)

Is it possible to disable things logged in External database (logs, live logs) from the standard mode ? Now, logs and live logs are both written into external AND standard database, it is useless to me.

Furthermore, is it possible to change the retention time for External logs ? I'd like to have 1 month of history in the standard log and 2 years on the external logs.

I read multiple docs about this new way of logging (https://docs.moodle.org/dev/Logging_2 et https://docs.moodle.org/29/en/Logs) but I couldn't find any answer about my questions above.

Thanks a lot for your help.

Cheers,