Good point. Yes, in theory they could be duplicated. I chose 6 characters firstly to keep the url as short as possible (I thought 5 chars was too short, 7 too long).
I am planning on introducing a background process to clean up shortened URL's that haven't been accessed in a given time frame (still deciding but I think around 7 days). While it still wouldn't solve the problem you mentioned at a certain scale, it would help. But true, I very much doubt it will ever reach that scale.
I am planning on introducing a background process to clean up shortened URL's that haven't been accessed in a given time frame (still deciding but I think around 7 days). While it still wouldn't solve the problem you mentioned at a certain scale, it would help. But true, I very much doubt it will ever reach that scale.
Thanks for the critique