MariaDB [zabbix]> DELETE FROM events WHERE (UNIX_TIMESTAMP(NOW()) - clock) > (@history_interval * 24 * 60 * 60);
ERROR 1036 (HY000): Table 'events' is read only
-rwxrwx--- 1 mysql mysql     2111 Jul 12 17:26 /var/lib/mysql/zabbix/events.frm*
-rwxrwx--- 1 mysql mysql 18874368 Aug 27 17:42 /var/lib/mysql/zabbix/events.ibd*
MariaDB [zabbix]> SHOW GRANTS;
+--------------------------------------------------------------------------+
| Grants for root@localhost                                                |
+--------------------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' WITH GRANT OPTION      |
| GRANT SELECT, INSERT, UPDATE, DELETE ON `zabbix`.* TO 'root'@'localhost' |
| GRANT PROXY ON ''@'%' TO 'root'@'localhost' WITH GRANT OPTION            |
+--------------------------------------------------------------------------+