mysql 表锁，redo log，binlog，undo log

redo log，binlog，undo log：https://juejin.cn/post/6987557227074846733

MDL锁：https://blog.csdn.net/q2878948/article/details/96430129

　　　　https://blog.csdn.net/finalkof1983/article/details/88063328