什么是柱状数据库？ [英] What is a columnar database?

问题描述

我已经在仓库工作了一段时间。

I have been working with warehousing for a while now.

我对柱状数据库感兴趣，以及他们为数据检索提供的速度。

I am intrigued by Columnar Databases and the speed that they have to offer for data retrievals.

多部分问题：

• 柱状数据库如何工作？


• 与关系数据库有什么不同？

推荐答案

p> 柱状数据库如何工作？

柱状数据库是一种概念 。换句话说，没有关于这些数据库如何工作的特定描述;事实上，一些是建立在传统的，面向行的DBMS上，只是将信息存储在具有一个（或者经常是两个）列的表中（并且添加必要的层以容易地访问列数据）。

How do Columnar Databases work?
Columnar database is a concept rather a particular architecture/implementation. In other words, there isn't one particular description on how these databases work; indeed, several are build upon traditional, row-oriented, DBMS, simply storing the info in tables with one (or rather often two) columns (and adding the necessary layer to access the columnar data in an easy fashion).

它们与关系数据库有什么不同？
它们通常不同于传统...

How do they differ from relational databases? They generally differ from traditional (row-oriented) databases with regards to ...

• 性能...


• 存储要求...


• 轻松修改模式...

特别地，它们在所提到的领域中提供了优点，当典型的用途是在有限数量的列上计算聚合值时，而不是尝试和使用DBMS 检索给定实体的所有/大多数列。

...in specific use cases of DBMSes.
In particular they offer advantages in the areas mentioned when the typical use is to compute aggregate values on a limited number of columns, as opposed to try and retrieve all/most columns for a given entity.

有一个试用版的柱状数据库，我可以安装来玩吗？ （我在Windows 7上）
是的，有柱状数据库的商业，免费和开源实现。请参阅 维基百科文章末尾的列表。 br>
请注意，介绍了其中几个实现来解决特定需求（例如占用空间很小，数据的高度可压缩分布或备用矩阵仿真等），而不是提供一般的面向列的DBMS本身。

Is there a trial version of a columnar database I can install to play around? (I am on Windows 7) Yes, there are commercial, free and also open-source implementation of columnar databases. See the list at the end of the Wikipedia article for starter.
Beware that several of these implementations were introduced to address a particular need (say very small footprint, highly compressible distribution of data, or spare matrix emulation etc.) rather than provide a general purpose column-oriented DBMS per-se.

注意：关于几个柱状DBMS的单一目的取向的评论不是对这些实现的批判，而是对DBMS的这种方法的另外的指示从更加自然（当然更广泛使用）的方法来存储记录实体。因此，当面向行的方法不令人满意时，使用这种方法，因此，并且倾向于以特定目的为目标
b）比工作接收更少的资源/兴趣

Note: The remark about the "single purpose orientation" of several columnar DBMSes is not a critique of these implementations, but rather an additional indication that such an approach for DBMSes strays from the more "natural" (and certainly more broadly used) approach to storing record entities. As a result, this approach is used when the row-oriented approach isn't satisfactory, and therefore and tends to
a) be targeted for a particular purpose b) receive less resources/interest than work on "General Purpose", "Tried and Tested", tabular approach.

默认情况下， Entity-Attribute-Value （EAV）数据模型，可能是您可能需要考虑的替代存储策略。虽然不同于纯粹的柱状DB模型，EAV具有Columnar DB的几个特征。

Tentatively, the Entity-Attribute-Value (EAV) data model, may be an alternative storage strategy which you may want to consider. Although distinct from the "pure" Columnar DB model, EAV shares several of the characteristics of Columnar DBs.

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