LL); SELECT * FROM t4; URL: https://mariadb.com/kb/en/timestamp/ 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 UNLOCK TABLES. FLUSH SSL --------- 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/https://mariadb.com/kb/en/show-replica-status/ 3 | 3 | 6 | | 4 | 4 | 8 | | 5 | 5 | 10 | | 6 | 8 | 14 | +------+------+------+ Another example, given the following data (the separator is a tab): 1 a 2 b The value of the first column is doubled before loading: LOAD DATA INFILE 'ld.txt' INTO TABLE ld (@i,v) SET i=@i*2; SELECT * FROM ld; +------+------+ | i | v | +------+------+ | 2 | a | | 4 | b | +------+------+ URL: https://mariadb.com/kb/en/load-data-infile/ROM t; +------+------+ | id | f1 | +------+------+ | 3 | b | | 4 | a | +------+------ URL: https://mariadb.com/kb/en/useful-mariadb-queries/https://mariadb.com/kb/en/explain/https://mariadb.com/kb/en/reserved-words/https://mariadb.com/kb/en/sql_modeoracle/https://mariadb.com/kb/en/date_format/ OS function to convert the data using the system time zone. At least on Linux, the corresponding function (localtime_r) uses a global mutex inside glibc that can cause contention under high concurrent load. Set your time zone to a named time zone to avoid this issue. See mysql time zone tables for details on how to do this. Examples -------- SELECT FROM_UNIXTIME(1196440219); +---------------------------+ | FROM_UNIXTIME(1196440219) | +---------------------------+ | 2007-11-30 11:30:19 | +---------------------------+ SELECT FROM_UNIXTIME(1196440219) + 0; +-------------------------------+ | FROM_UNIXTIME(1196440219) + 0 | +-------------------------------+ | 20071130113019.000000 | +-------------------------------+ SELECT FROM_UNIXTIME(UNIX_TIMESTAMP(), '%Y %D %M %h:%i:%s %x'); +---------------------------------------------------------+ | FROM_UNIXTIME(UNIX_TIMESTAMP(), '%Y %D %M %h:%i:%s %x') | +---------------------------------------------------------+ | 2010 27th March 01:03:47 2010 | +---------------------------------------------------------+ URL: https://mariadb.com/kb/en/from_unixtime/