MySQL引擎

MySQL 1.5.X之前是MyISAM,之后就是InnoDB

查看MySQL引擎

mysql> show engines;
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| Engine             | Support | Comment                                                        | Transactions | XA   | Savepoints |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| FEDERATED          | NO      | Federated MySQL storage engine                                 | NULL         | NULL | NULL       |
| MRG_MYISAM         | YES     | Collection of identical MyISAM tables                          | NO           | NO   | NO         |
| MyISAM             | YES     | MyISAM storage engine                                          | NO           | NO   | NO         |
| BLACKHOLE          | YES     | /dev/null storage engine (anything you write to it disappears) | NO           | NO   | NO         |
| CSV                | YES     | CSV storage engine                                             | NO           | NO   | NO         |
| MEMORY             | YES     | Hash based, stored in memory, useful for temporary tables      | NO           | NO   | NO         |
| ARCHIVE            | YES     | Archive storage engine                                         | NO           | NO   | NO         |
| InnoDB             | DEFAULT | Supports transactions, row-level locking, and foreign keys     | YES          | YES  | YES        |
| PERFORMANCE_SCHEMA | YES     | Performance Schema                                             | NO           | NO   | NO         |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+

查看当前库的引擎

先 use 某数据库

mysql> show variables like '%storage_engine%';
+----------------------------+--------+
| Variable_name              | Value  |
+----------------------------+--------+
| default_storage_engine     | InnoDB |
| default_tmp_storage_engine | InnoDB |
| storage_engine             | InnoDB |
+----------------------------+--------+

查看当前表的引擎

最后一行


mysql> show create table account;
+---------+--------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table   | Create Table                                                                                                                                                 |
+---------+--------------------------------------------------------------------------------------------------------------------------------------------------------------+
| account | CREATE TABLE `account` (
  `id` int(11) DEFAULT NULL,
  `name` varchar(22) DEFAULT NULL,
  `age` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+---------+--------------------------------------------------------------------------------------------------------------------------------------------------------------+

查看当前MySQL服务器版本

select version();

+-----------+
| version() |
+-----------+
| 5.6.46    |
+-----------+

MylSAM和InnoDB的区别

1、MyISAM是非事务安全的,而InnoDB是事务安全的

2、MyISAM锁的粒度是表级的,而InnoDB支持行级锁

3、MyISAM支持全文类型索引,而InnoDB不支持全文索引

4、MyISAM相对简单,效率上要优于InnoDB,小型应用可以考虑使用MyISAM

5、MyISAM表保存成文件形式,跨平台使用更加方便

6、MyISAM管理非事务表,提供高速存储和检索以及全文搜索能力,如果在应用中执行大量select操作可选择

7、InnoDB用于事务处理,具有ACID事务支持等特性,如果在应用中执行大量insert和update操作,可选择。

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