Mostly mistaken and ignored parameters while optimizing a #PostgreSQL #database - #Percona Live 2020

Thanks for this video. I have learnt a lot. I have one question. I upgraded from postgresql 9.6 to 10.10. The server was slow and after doing some tuning on the server nothing worked. But when we down graded back to postgresql 9.6, performance improved. What could be the root of poor performance when the server was upgraded to 10.10?

Is there a link to the slides somewhere?