database 为什么数据库总是用圆柱体表示？
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Why is a database always represented with a cylinder?
提问by Rodney S. Foley
This question came up today and I couldn't find any historical answer as to why a database is always represented as a cylinder. I am hoping someone in the stack world would know why and have a link or something backing it up.
今天出现了这个问题，我找不到任何关于为什么数据库总是表示为圆柱体的历史答案。我希望堆栈世界中的某个人会知道原因并有一个链接或支持它的东西。
回答by Jerry Coffin
I'm reasonably certain that it predates disk drives, and goes back to a considerably older technology: drum memory:
我有理由肯定它早于磁盘驱动器，并且可以追溯到相当古老的技术：鼓式存储器：
Another possibility (or maybe the choice was based on both) is a still older technology: mercury tank memory:
另一种可能性（或者可能是基于两者的选择）是一种更古老的技术：水银罐存储器：
You may have seen the symbol oriented horizontally instead of vertically, but horizontal drums were common as well:
您可能已经看到了水平方向而非垂直方向的符号，但水平鼓也很常见：
回答by jungledev
You asked for more pics. I took these at the computer history museum in Mountain View, CA in May 2016. 
Description for the above image says:
你要了更多的照片。我于 2016 年 5 月在加利福尼亚州山景城的计算机历史博物馆拍摄了这些照片。上图的 说明说：
UNIVAC I mercury memory tank, Remington Rand, US, 1951
UNIVAC I 水银记忆罐，美国雷明顿兰德公司，1951 年
For memory, the UNIVAC used seven mercury delay line tanks. Eighteen pairs of crystal transducers in each tank transmitted and received data as waves in mercury held at a constant 149°F
为了记忆，UNIVAC 使用了七个汞延迟线罐。每个水箱中的 18 对晶体传感器以恒定 149°F 的水银波形式发送和接收数据
Gift of William Agee X976.89
威廉·艾吉的礼物 X976.89
Description for the above image says:
上图的描述说：
Williams-Kilburn tube - Manchester Mark I, Manchester University, UK, ca 1950
威廉姆斯-基尔本管 - 曼彻斯特马克一世，英国曼彻斯特大学，约 1950 年
This was the memory in the Manchester Mark I, the successor to the "Baby." It stored only 128 40-bit words. Each bit was an electric charge that created a spot of light on the face of a "TV tube."
这是“宝贝”的继任者曼彻斯特马克一世的记忆。它仅存储 128 个 40 位字。每一位都是一个电荷，在“电视管”的表面上产生一个光点。
Gift of Manchester University Computer Science Department, X67.82
曼彻斯特大学计算机科学系的礼物，X67.82
回答by Matt Rogish
It's because people view a DB as simple storage, much like a disk. And disk storage has always been represented by a cylinder due to, well, the physical properties of spinning magnetic disks.
这是因为人们将数据库视为简单的存储，很像磁盘。由于旋转磁盘的物理特性，磁盘存储一直用柱面表示。
回答by Matt Curtis
It comes from the olden days (pre 1960) when data was analog, i.e. round. Nowadays with digital (square) data, databases aren't cylindrical but unfortunately the convention has stuck.
它来自过去（1960 年之前），当时数据是模拟的，即圆形。如今，对于数字（方形）数据，数据库不是圆柱形的，但不幸的是，约定俗成。
回答by user3285800
I always assumed it stood for the round edges of a hard drive platter. The average consumer might not have necessarilyknown what a Physical Hard Drive Componentlooked like, so it was represented as a cylinder.
我一直认为它代表硬盘盘的圆边。普通消费者可能不一定知道物理硬盘驱动器组件是什么样子，因此它被表示为圆柱体。
