I want to make a question if anyone has upgraded Metabase (Ver. 0.30 or Ver. 0.31) with Postgres 11. Is there was any problem?
Finally, I did the upgrade to Postgres 11 with success. So there is no problem with latest metabase version. Also, I advice you to activate the JIT feature of Postgres that gives you a boost of 100%, at least, on query performance speed.