I'm a young upstart programmer and I've never actually seen a database. But computers in large part come in boxes, not in cylinders so I was wondering why they are always represented as a cylinder when people show their architecture drawings.

Is there a reason why or is it just tradition to draw them like that?


4 Answers 4


The icon is probably meant to represent an old-school disk pack like this


mainly because databases typically reside on a large random-access device like an HDD.

  • 4
    I like the way the operator is stroking it :)
    – Ian
    Commented Apr 10, 2012 at 12:00

Although I don't have a specific reference to cite, I took it to represent a hard drive. Historically, hard drives store data magnetically on round cylinders. Since databases are all about persistance, hard drives are the mechanism for doing so.


Because their main purpose is to write data to a cylinder (disk).

  • 3
    I suppose a platter is a very very short cylinder.
    – Dan Ray
    Commented Apr 9, 2012 at 19:55
  • @DanRay - or you have many platters which resemple a cylinder.
    – JeffO
    Commented Apr 9, 2012 at 19:58
  • 9
    Before there were disks, there was drum storage (or drum memory).
    – OldFart
    Commented Apr 9, 2012 at 20:07

I've always looked at the icon more as a silo than a cylinder: that is, a large high-volume container that can store loads of grain/salt/data.

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