1. inner join、left join、right join
6. tinyint 、 smallint 、mediumint 、int 、 bigint
10. tinytext、text、mediumtext、longtext
20. login shell、non-login shell config file
1. If-Modified-Since Last-Modified
2. Accept-Encoding Content-Encoding
1. --with-http_stub_status_module
2. worker_processes、worker_cpu_affinity
8. kafka unclean.leader.election
12. kafka kafka-consumer-groups.sh