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databasedatabase-designdiagramdiagrammingdatabase-diagramming

Why is a database always represented with a cylinder?


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.


Solution

  • I'm reasonably certain that it predates disk drives, and goes back to a considerably older technology: drum memory:

    Drum Memory

    Another possibility (or maybe the choice was based on both) is a still older technology: mercury tank memory:

    Mercury tank

    You may have seen the symbol oriented horizontally instead of vertically, but horizontal drums were common as well:

    Multiple horizontal drums