BANG file

A BANG file(balanced and nested grid file) is a point access method which divides space into a nonperiodic grid. Each spatial dimension is divided by a linear hash. Cells may intersect, and points may be distributed between them. In some early ICL mainframe computers, a bang file was a temporary data storage file whose name began with a ! character (which is sometimes nicknamed 'bang') and automatically deleted when the run or user session ended. http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.77.7345&rep=rep1&type=pdf