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.
+5
A:
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.
Matt Rogish
2010-05-12 20:50:11
+2
A:
I don't have any proof but I always assumed the cylinder of database represented a hard-drive disk.
Sailing Judo
2010-05-12 20:51:31
+1
A:
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.
Matt Curtis
2010-05-12 20:53:12
If analog = round and digital = square why are magnetic (digital) hard drive platers round and old analog computers giant rectangles?http://www.buzzvines.com/files/images/western_digital_green_2tb_HHD.jpghttp://xpda.com/junkmail/junk162/GPN-2000-000354.jpg
Rodney Foley
2010-05-12 21:28:18
Aw, downvotes? Bah humbug!
Matt Curtis
2010-05-12 21:29:44
@Creepy Gnome: awesome counter, but I bet they're 'shopped by digital revisionists :D
Matt Curtis
2010-05-12 21:30:54
+1 to balance the people who did not understand the Calvin and Hobbes "The world was in black and white before the 50's" style reference. (You see it is a color picture of a black and white world.)
Ukko
2010-05-12 22:04:37
+11
A:
I'm reasonably certain that it predates disk drives, and goes back to a considerably older technology: drum memory:
Edit: doing a bit more looking around, here's a better picture:
Jerry Coffin
2010-05-12 21:02:27
Based on some of my own additional research this is the best and most plausible answer. The first databases appear to have used storage drums which where giant cylinders and it is very likely that when they represented them on paper diagrams they would use a cylinder to be the database.
Rodney Foley
2010-05-12 21:19:40
I'm not enough of an expert on the history of computing to know if this answer truly is accurate, though I believe this is correct, but in any case +1 for the cool pictures of long-gone technology!
DarenW
2010-09-21 17:27:15