
* Free memory and file descriptors for tables not in use from table list
* Lock given tables as read.
* Wait until all background writes are suspended and tables are marked as
closed.
* Check that all tables supports FOR EXPORT
* No changes to these tables allowed until UNLOCK TABLES

This is basically the same behavior as in old MariaDB version if one first
lock the tables, then do FLUSH TABLES. The tables will be copyable until

FLUSH SSL
---------

MariaDB starting with 10.4
--------------------------
The FLUSH SSL command was first added in MariaDB 10.4.

In MariaDB 10.4 and later, the FLUSH SSL command can be used to dynamically
reinitialize the server's TLS context. This is most useful if you need to
replace a certificate that is about to expire without restarting the server.

This operation is performed by reloading the files defined by the following
TLS system variables:

* ssl_cert
* ssl_key
* ssl_ca
* ssl_capath
* ssl_crl
* ssl_crlpath

These TLS system variables are not dynamic, so their values can not be changed
without restarting the server.

If you want to dynamically reinitialize the server's TLS context, then you
need to change the certificate and key files at the relevant paths defined by
these TLS system variables, without actually changing the values of the
variables. See MDEV-19341 for more information.

Reducing Memory Usage
---------------------

To flush some of the global caches that take up memory, you could execute the
following command:

FLUSH LOCAL HOSTS,
 QUERY CACHE,
 TABLE_STATISTICS,
 INDEX_STATISTICS,
 USER_STATISTICS;

URL: https://mariadb.com/kb/en/flush/