Creating your own TinyURL

Question

I have just found this great tutorial as it is something that I need.

However, after having a look, it seems that this might be inefficient. The way it works is, fir

Answer 1

I don't know why you'd bother. The premise of the tutorial is to create a "random" URL. If the random space is large enough, then you can simply rely on pure, dumb luck. If you random character space is 62 characters (A-Za-z0-9), the the 4 characters they use, given a reasonable random number generator, is 1 in 62^4, which is 1 in 14,776,336. Five characters is 1 in 916,132,832. So, a conflict is, literally, "1 in a billion".

Obviously, as the documents fill, your odds increase for the chance of a collision.

With 10,000 documents, it's 1 in 91,613, almost 1 in 100,000 (for round numbers).

That means, for every new document, you have a 1 in 91,613 chance of hitting the DB again for another pull on the slot machine.

It is not deterministic. It's random. It's luck. In theory, you can hit a string of really, really, bad luck and just get collision after collision after collision. Also, it WILL, eventually, fill up. How many URLs do you plan on hashing?

But if 1 in 91,613 odds isn't good enough, boosting it to 6 chars makes it more than 1 in 5M for 10,000 documents. We're talking almost LOTTO odds here.

Simply put, make the key big enough (7 characters? 8?) and the problem pretty much "wishes" itself out of existence.