版本相關
show variables like 'version%'
version 5.7.28
version_comment MySQL Community Server (GPL)
version_compile_machine x86_64
version_compile_os Linux
密碼相關
show variables like 'validate%'
validate_password_check_user_name OFF
validate_password_dictionary_file
validate_password_length 8
validate_password_mixed_case_count 1
validate_password_number_count 1
validate_password_policy MEDIUM
validate_password_special_char_count 1
例如：
修改密碼長度：set global validate_password_length=6;
字符集相關
show variables like 'character%'
character_set_client utf8mb4
character_set_connection utf8mb4
character_set_database utf8
character_set_filesystem binary
character_set_results utf8mb4
character_set_server latin1
character_set_system utf8
character_sets_dir /usr/share/mysql/charsets/
進程相關
show variables like '%max_connection%';
max_connections 2048
show status like 'Threads%';
Threads_cached 0
Threads_connected 467
Threads_created 467
Threads_running 1