mysqldump ignores some internal tables by default, such as:

• mysql.apply_status
• mysql.schema
• mysql.general_log
• mysql.slow_log
• mysql.transaction_registry

See here:

https://github.com/MariaDB/server/blob/mariadb-10.4.8/client/mysqldump.c#L1001

I think the following tables should also be ignored by default:

• mysql.innodb_index_stats
• mysql.innodb_table_stats

The reason is that if someone tries to import a dump created by mysqldump, then a race condition between the import and the InnoDB persistent statistics calculation exists, and the user can see errors like this:

Duplicate 'PRIMARY-n_diff_pfx01' for key 'primary' for database 'xxxx98'.

This was reported long ago in the following upstream bug report:

https://bugs.mysql.com/bug.php?id=71814

The workaround mentioned in that bug report is to disable InnoDB persistent statistics prior to the import:

SET GLOBAL innodb_stats_auto_recalc=0;

SET GLOBAL innodb_stats_persistent=0;

However, it would be more ideal to make this workaround unnecessary by fixing the problem.