????????morgo?????suggested by morgo??? Impact of column types on MySQL JOIN performance???????????????????????ЩС?????????????????????????????????? (aka MySQL versions).
????The answer
??????????????????????????Щ????????????? :-)
????The test
????SELECT * FROM a JOIN b ON b.a_id = a.id WHERE a.id BETWEEN 10000 AND 15000 ;
???????????в??????????????????
????MySQL?????????????????????????? join buffer???????????????buffers (read_buffer_size??read_rnd_buffer_size??join_buffer_size)??
????innodb_buffer_pool_size = 768M innodb_buffer_pool_instances = 1 innodb_file_per_table = 1
????The results