在mysql的官网上看到在mysql5.5以上的版本中已经更改了默认的存储引擎，在5.5版本以前是Myisam以后是Innodb.
14.1. InnoDB as the Default MySQL Storage Engine
MySQL has a well-earned reputation for being easy-to-use and delivering performance and scalability. Prior to MySQL 5.5, MyISAM was the default storage engine. In our experience, most users never changed the default settings. In MySQL 5.5 and higher, InnoDB is the default storage engine. Again, we expect most users will not change the default settings. But, because of InnoDB, the default settings deliver the benefits users expect from their RDBMS: ACID Transactions, Referential Integrity, and Crash Recovery. Let's explore how using InnoDB tables improves your life as a MySQL user, DBA, or developer.