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数据压缩定义

[英]Data compression definition

原文 2014-03-04 16:48:14 8 1 database/ compression/ db2

Could anyone explain the term "Data compression" in database ( lame words ). 谁能解释数据库中的"Data compression"一词（ lame words ）。 Sorry if this question is simple, but it does help me. 抱歉，这个问题很简单，但确实对我有帮助。

I did find the technical definition, but still did not get a right understanding. 我确实找到了技术定义，但是仍然没有正确的理解。

Data compression saves space and saves reading times and so on. 数据压缩可节省空间并节省读取时间等。 Does that mean its aggregating data in the table? 这是否意味着其汇总表中的数据？ Please clarify 请澄清

1 个解决方案

Since you've tagged this post with db2 , then I'm assuming your asking about compression within the database. 由于您已使用db2标记了此帖子，所以假设您要询问数据库内的压缩情况。 DB2 does dictionary compression – it replaces common strings with shorter tokens on the actual data pages, reducing the size of the table. DB2进行字典压缩–它将实际数据页面上的通用字符串替换为较短的标记，从而减小了表的大小。

Please see: The wikipedia article on Dictionary Coder for a general discussion on how this algorithm works. 请参阅：关于词典编码器的Wikipedia文章，以对该算法如何工作进行一般性讨论。

If you're using DB2 for Linux, UNIX and Windows you can read this developerWorks article that describes the compression specifically in DB2. 如果您将DB2用于Linux，UNIX和Windows，则可以阅读这篇developerWorks文章，其中专门描述了DB2中的压缩。 The article is a few years old but it holds true today (even though there have been many enhancements beyond the initial release). 这篇文章已有几年历史了，但是今天仍然适用（即使在初始发行版之后进行了许多增强）。