重点是这几个参数：
tmp_table_size = 10240M
max_heap_table_size = 10240M
read_buffer_size =1024M
还有一些其它参数也建议调整：
max_allowed_packet = 32M
table_open_cache = 1024
sort_buffer_size = 4096M
join_buffer_size = 4096M
net_buffer_length = 32M
read_buffer_size = 1024M
read_rnd_buffer_size = 512M
thread_concurrency = 24
tmp_table_size = 10240M
max_heap_table_size = 10240M
myisam_sort_buffer_size = 8096M
