Google was granted a patent today on the way that they store, retrieve, and draw geospatially organized data in systems like Google Earth.
Server for geospatially organized flat file data
Invented by Chikai J. Ohazama, Phillip C. Keslin, and Mark A. Aubin
Assigned to Google
US Patent 7,225,207
Granted May 29, 2007
Filed October 10, 2002
A flat file data organization technique is used for storing and retrieving geospatially organized data. The invention reduces transfer time by transferring a few large files in lieu of a large number of small files. It also moves the process of locating a given data file away from the file system to a proprietary code base. Additionally, the invention simplifies database management by having quadtree packets generated on demand.
It’s impossible to tell for sure if this is the file system that Google is presently using for Google Earth, but the Earth Server Data Stream described in the patent appears to have been amongst the technology used by Google acquisition Keyhole Corp. An article about it from a few years ago: