MYSQL 术语（官网翻译）-A

翻译水平有限，供英语不太好的朋友做个参考，欢迎大家提意见。 官网链接 https://dev.MySQL.com/doc/refman/5.5/en/glossary.html 这些术语普遍应用在mysql服务器的相关信息中。这个作为InnoDB存储引擎相关术语的一个参考，而且多数的定义都和InnoDB相关。

.ARM file

ARCHIVE表的元数据。和.ARZ文件形成对比。以此作为扩展名的文件总是包含由MySQL EnterPRise Backup 的mysqlbackup命令生成的备份。 参见 .ARZ file, MySQL Enterprise Backup, mysqlbackup command。

.ARZ file

ARCHIVE表的数据。和.ARM文件形成对比。以此作为扩展名的文件总是包含由MySQL Enterprise Backup 的mysqlbackup命令生成的备份。 参见 .ARZ file, MySQL Enterprise Backup, mysqlbackup command。

ACID

这个大家都知道，就不罗嗦了。 参见atomic, commit, concurrency, doublewrite buffer, isolation level, locking, rollback, transaction。

adaptive flushing

这是一种为了缓解InnoDB表由检查点引入的I/O开销的算法。mysql定期地刷新修改页的小集合，而不是把缓存池中的所有修改页立即刷新到数据文件中。适应性刷新算法通过评估执行这些定期刷新的最佳比率，基于刷新比率和redo信息生成的速度，扩展了这个进程。 参见 buffer pool, checkpoint, data files, flush, InnoDB, page, redo log。

adaptive hash index

An optimization for InnoDB tables that can speed up lookups using = and IN 这是一种通过在内存中构建哈希索引，使用=和IN分隔符来加速InnoDB表的优化手段。

Operators, by constructing a hash index in memory. MySQL monitors index searches for InnoDB tables, and if queries could benefit from a hash index, it builds one automatically for index pages that are frequently accessed. In a sense, the adaptive hash index configures MySQL at runtime to take advantage of ample main memory, coming closer to the architecture of main-memory databases. This feature is controlled by the innodb_adaptive_hash_index configuration option. Because this feature benefits some workloads and not others, and the memory used for the hash index is reserved in the buffer pool, typically you should benchmark with this feature both enabled and disabled. The hash index is always built based on an existing InnoDB secondary index, which is organized as a B-tree structure. MySQL can build a hash index on a prefix of any length of the key defined for the B-tree, depending on the pattern of searches against the index. A hash index can be partial; the whole B-tree index does not need to be cached in the buffer pool. In MySQL 5.6 and higher, another way to take advantage of fast single-value lookups with InnoDB tables is to use the InnoDB memcached plugin. See InnoDB memcached Plugin for details.

参见 B-tree, buffer pool, hash index, memcached, page, secondary index。