myisam_max_[extra]_sort_file_size足够大
delay_key_write减少io,提高写入性能
bulk_insert_buffer_size
concurrent_insert 设置为2
read_rnd_buffer_size random scan 使用
read_buffer_size 顺序扫描表使用
key cache 的三种方式
key cache 预加载
SET GLOBAL hot_cache.key_buffer_size=16m
SET BLOBAL cold_cache.key_buffer_size=16m
CACHE INDEX example.top_message IN hot_cache
CACHE INDEX example.event IN cold_cache
LOAD INDEX INTO CACHE example.top_message,example.event IGNORE LEAVES
LOAD INDEX INTO CACHE example.user IGNORE LEAVERS,expamle.groups
