So, if there is an undetectable corrupted segment on the network once every 34 hours or even once a month, why aren't the databases hopelessly corrupt? Why aren't applications randomly failing? Well, in many cases a corrupt segment is no big deal. For example, a bad ACK segment will be ignored; a corrupt byte or two in am image file will probably not be noticed, and no one would be surprised if a document I sent them had a spelling error.