It's the smart thing to do - 4.3 billion is not that much.
I had some students that asked me if even a long would be enough to handle exponential growth, after all it's only twice as big. As a thought experiement I asked them to come up with a time to fill a 32 bit int completely. They came up with roughly a year. Then as a margin of error I said, let's assume you have 4.3 billion transactions every second instead. This volume can be sustained for 100 years, and we're still not in the danger zone yet.
One is 32 bits, the other is 64 bits. It occupies exactly twice as much space. It can contain far more information, but it is only twice as big on the harddrive.
I had some students that asked me if even a long would be enough to handle exponential growth, after all it's only twice as big. As a thought experiement I asked them to come up with a time to fill a 32 bit int completely. They came up with roughly a year. Then as a margin of error I said, let's assume you have 4.3 billion transactions every second instead. This volume can be sustained for 100 years, and we're still not in the danger zone yet.