数据库-表引擎

# 表引擎  ----------------+--------------+------+------------+
| FEDERATED          | NO      | Federated MySQL storage engine
                | NULL         | NULL | NULL       |
| MRG_MYISAM         | YES     | Collection of identical MyISAM tables
                | NO           | NO   | NO         |
| MyISAM             | DEFAULT | MyISAM storage engine
                | NO           | NO   | NO         |
| BLACKHOLE          | YES     | /dev/null storage engine (anything you wri
 it disappears) | NO           | NO   | NO         |
| CSV                | YES     | CSV storage engine
                | NO           | NO   | NO         |
| MEMORY             | YES     | Hash based, stored in memory, useful for t
ary tables      | NO           | NO   | NO         |
| ARCHIVE            | YES     | Archive storage engine
                | NO           | NO   | NO         |
| InnoDB             | YES     | Supports transactions, row-level locking,
oreign keys     | YES          | YES  | YES        |
| PERFORMANCE_SCHEMA | YES     | Performance Schema
                | NO           | NO   | NO         |

    myisam 更加稳定 效率高
    innodb 支持事务相对安全 myisam不支持事务
    myisam 生成三个文件 .frm(结构) .MYD(存储数据) .MYI(存储表的索引)
    innodb 生成一个文件 .frm 存储表的结构
    myisam 会产生碎片空间 innodb会自动回收