情景一:insert into table1 ...select * from table2:table1锁表,table2逐步锁(扫描一个锁一个)
情景二:insert into table1 ...select * from table2
order by 主键:table1锁表,table2逐步锁(扫描一个锁一个)
情景三:insert into table1 ...select * from table2
order by 非主键:table1锁表,table2一开始就锁全表