MySQL 8: Truncate table stuck in `checking permissions` state for minutes Sometimes but not always truncate table statements get stuck in checking permissions state for several minutes (up to 7-8 minutes). 

I'm running MySQL 8.0.12 (for Linux on x86_64 (MySQL Community Server - GPL))
My tables are partitioned with around 365 partitions in each.

There are only 5 users (excluding root and mysql.). The 5 users are not tied to a specific host. Sometimes the same users is used from multiple hosts at same time.

Is this a known problem? What are the possible causes or solutions?

Any help is much appreciated!
Hence my advice not to have more than about 50 partitions in a table.  Or to abandon partitioning altogether.

What may be happening:  table_open_cache (or one of the other caches) may be too small, and, hence, thrashing.

To verify that theory, I need to check several things.  Please provide SHOW GLOBAL STATUS;, SHOW VARIABLES; and how much RAM you have.  More details.

To critique the partitioning, please provide SHOW CREATE TABLE for at least one of the tables with a lot of partitions.

And you are TRUNCATEing a table with a lot of partitions?

If possible, look in the filesystem and list some of the files for that table.