MySQL 事务锁结构解释

Question

当以下查询在 MySQL DB 上运行时

SHOW ENGINE INNODB STATUS;

输出包含以下形式的 TRANSACTIONS 部分

---TRANSACTION 352221071982, ACTIVE 783 sec unlock_row/inserting
mysql tables in use 3, locked 1
102556 lock struct(s), heap size 376, 20000 row lock(s)
MySQL thread id 61619, OS thread handle 0x2b11e3207700, query id 4861037 user_ip user Creating sort index
/* ApplicationName= */ UPDATE Table ...
Trx read view will not see trx with id >= 352221071983, sees < 352221057548

---TRANSACTION 352221063355, ACTIVE 1489 sec inserting
mysql tables in use 2, locked 2
167844 lock struct(s), heap size 376, 11245319 row lock(s), undo log entries 11077479
MySQL thread id 61777, OS thread handle 0x2b11e5a46700, query id 4851071 user_ip username copy to tmp table

什么是锁结构，锁结构和行锁之间有关系吗？我们应该注意锁结构的巨大价值吗？还是行锁才重要？