Multi-dimensional spatial index for a geographic database

A computer-implemented index stored on a computer readable storage medium for a geographic database containing geographic data that represent geographic features, said index comprising:

• a single index structure that includes two spatial dimensions and a non-spatial third dimension, wherein said two spatial dimensions define a bounded area represented by a maximum latitude, a maximum longitude, a minimum latitude and a minimum longitude,
• wherein said single index structure is a k-d-tree index structure comprising a root node, intermediate nodes and leaf nodes, wherein each node is part of a parent-child relationship wherein each parent node includes control information from which one of at least two child nodes associated with the parent node are distinguishable based on a search key,
• said geographic data indexed by said single index structure are searchable spatially using computer-executable instructions and said two spatial dimensions of said single index structure and a latitude and a longitude, said geographic data indexed by said single index structure are searchable for a non-spatial property of the indexed geographic data that represent the geographic features using computer-executable instructions and said third dimension of said single index structure, wherein said non-spatial property of the geographic data includes a rank associated with the geographic features represented by the geographic data, a granularity of said indexed geographic data, and a scale associated with said indexed geographic data, wherein said data that represent geographic features are organized into layers based on said rank associated with the represented features.

A computer-implemented index stored on a computer readable storage medium comprising:

• a single k-d tree indexing structure that includes a first dimension, a second dimension and a third dimension, wherein said k-d-tree index structure comprising a root node, intermediate nodes and leaf nodes, wherein each node is part of a parent-child relationship wherein each parent node includes control information from which one of at least two child nodes associated with the parent node are distinguishable based on a search key,
• wherein the k-d tree indexing structure is used to index parcels of geographic data, wherein said parcels are collections of said geographic data that represent geographic features encompassed within a bounded area;
• wherein said first dimension includes latitude boundary information of said bounded area,
• wherein said second dimension includes longitude boundary information of said bounded area, wherein said latitude boundary information and said longitude boundary information define said bounded area represented by a maximum latitude, a maximum longitude, a minimum latitude and a minimum longitude, said parcels of geographic data indexed by said single indexing structure are searchable using computer-executable instructions and a latitude value, a longitude value and said first and second dimension of said indexing structure,
• wherein said third dimension includes rank information that has at least two levels, wherein a first level of rank is associated with geographic features of greater importance and a second level of rank is associated with the geographic features of lesser importance, said data indexed by said single indexing structure is searchable for said rank using computer-executable instructions and said third dimension of said single indexing structure.