Receiving serial port data: real-time web display + logging (with downsampling)

I am working on a small project which involves displaying and recording (for later processing) data received through a serial port connection from some sort of measurement device. I am using a Raspberry Pi to read and store the received information: this is done with a small program written in Python which opens the serial device, reads a frame and stores the data in a MySQL database (there is no need to poll or interact with the device, data is sent automatically).I am working on a small project which involves