gap lock 释义：
锁的差距
例句：
They do not prevent different transactions from taking gap locks on the same gap. Thus， a gap X-lock has the same effect as a gap S-lock.
他们并不会阻止不同的事务在相同的间隙获取锁，因此间隙读锁和间隙写锁有相同的影响。
next lock 释义：
下一个锁
例句：
Says he'll catch me up at the next lock.
说他在下道水闸那边援我碰头。
