@matthewb - I’m delighted to let you know that I’ve finally done the migration. I had to create a very robust script that does “all for me”, by running mydumper, fix the schemas/scripts, run myloader, compare all COUNT(*), tables, databases, etc… Tested very well, and ran today in production. All successful!
However… I’m having serious Performance problems, mostly because the way Percona is using indexes seem to be quite different than MariaDB, and in some queries, I don’t seem to be able to FORCE INDEX usage to the way it was doing in MariaDB.
In another query, it seems to be using the same/expected indexes and rows examined, but while in MariaDB all components of the EXPLAIN are “Using where”, in Percona one of them is doing “Using filesort”, which is causing the performance issue, I think.
I tried to set the “optimized_switch” to the same as MariaDB (well, at least those that exist on Percona too), but it didn’t seem to resolve the problem.
Thank you!