Grid file

In computer science, a grid file or bucket grid is a point access method which splits a space into a non-periodic grid where one or more cells of the grid refer to a small set of points. Grid files (a symmetric data structure) provide an efficient method of storing these indexes on disk to perform complex data lookups. In computer science, a grid file or bucket grid is a point access method which splits a space into a non-periodic grid where one or more cells of the grid refer to a small set of points. Grid files (a symmetric data structure) provide an efficient method of storing these indexes on disk to perform complex data lookups. It provides a grid of n-dimensions where n represents how many keys can be used to reference a single point. Grid files do not contain any data themselves but instead contain references to the correct bucket. A grid file is usually used in cases where a single value can be referenced by multiple keys. A grid file began being used because 'traditional file structures that provide multikey access to records, for example, inverted files, are extensions of file structures originally designed for single-key access. They manifest various deficiencies in particular for multikey access to highly dynamic files.' In a traditional single dimensional data structure (e.g. hash), a search on a single criterion is usually very simple but searching for a second criterion can be much more complex.