最開(kāi)始用MySQL Administrator建數(shù)據(jù)庫(kù)的時(shí)候，表缺省是InnoDB類型，也就沒(méi)有在意。后來(lái)用Access2MySQL導(dǎo)數(shù)據(jù)的時(shí)候發(fā)現(xiàn)只能導(dǎo)成MyISAM類型的表，不知道這兩種類型有什么區(qū)別，就去查了查。原來(lái)是MyISAM類型不支持事務(wù)處理等高級(jí)處理，而InnoDB類型支持。MyISAM類型的表強(qiáng)調(diào)的是性能，其執(zhí)行數(shù)度比InnoDB類型更快，但是不提供事務(wù)支持，而InnoDB提供事務(wù)支持已經(jīng)外部鍵等高級(jí)數(shù)據(jù)庫(kù)功能。這樣就可以根據(jù)數(shù)據(jù)表不同的用處是用不同的存儲(chǔ)類型。
另外，MyISAM類型的二進(jìn)制數(shù)據(jù)文件可以在不同操作系統(tǒng)中遷移。也就是可以直接從Windows系統(tǒng)拷貝到linux系統(tǒng)中使用。
Storage Engines and Table Types MySQL supports several storage engines that act as handlers for different table types. MySQL storage engines include both those that handle transaction-safe tables and those that handle non-transaction-safe tables:
The original storage engine was ISAM, which managed non-transactional tables. This engine has been replaced by MyISAM and should no longer be used. It is deprecated in MySQL 4.1, and is removed in subsequent MySQL release series.
In MySQL 3.23.0, the MyISAM and HEAP storage engines were introduced. MyISAM is an improved replacement for ISAM. The HEAP storage engine provides in-memory tables. The MERGE storage engine was added in MySQL 3.23.25. It allows a collection of identical MyISAM tables to be handled as a single table. All three of these storage engines handle non-transactional tables, and all are included in MySQL by default. Note that the HEAP storage engine has been renamed the MEMORY engine.
The InnoDB and BDB storage engines that handle transaction-safe tables were introduced in later versions of MySQL 3.23. Both are available in source distributions as of MySQL 3.23.34a. BDB is included in MySQL-Max binary distributions on those operating systems that support it. InnoDB also is included in MySQL-Max binary distributions for MySQL 3.23. Beginning with MySQL 4.0, InnoDB is included by default in all MySQL binary distributions. In source distributions, you can enable or disable either engine by configuring MySQL as you like.
The EXAMPLE storage engine was added in MySQL 4.1.3. It is a “stub” engine that does nothing. You can create tables with this engine, but no data can be stored in them or retrieved from them. The purpose of this engine is to serve as an example in the MySQL source code that illustrates how to begin writing new storage engines. As such, it is primarily of interest to developers.
NDB Cluster is the storage engine used by MySQL Cluster to implement tables that are partitioned over many computers. It is available in source code distributions as of MySQL 4.1.2 and binary distributions as of MySQL-Max 4.1.3.
The ARCHIVE storage engine was added in MySQL 4.1.3. It is used for storing large amounts of data without indexes in a very small footprint.
The CSV storage engine was added in MySQL 4.1.4. This engine stores data in text files using comma-separated values format.
The BLACKHOLE storage engine was added in MySQL 4.1.11. This engine accepts but does not store data and retrievals always return an empty set.