An Indexing Method for Spatial Databases

In this paper, we introduce an indexing method for accessing spatial databases. The index structure described here is multi-dimensional and is an extension of Multilevel Grid File (MLGF) combined with the z-ordering technique to efficiently handle indexing on the spatial components of the objects. The other important property of the proposed index structure is to be able to index on fuzzy information and process fuzzy querying in spatial databases. Handling spatial, aspatial data and fuzzy information in the physical database is necessary to satisfy some of the requirements of the spatial database applications, i.e., the geographic information systems (GIS) applications. With our proposed multi-dimensional index structure (we call it ExMLGF in this paper), one can create an index structure on aspatial (and fuzzy) data along with spatial data on the same index structure and process aspatial, spatial queries and fuzzy/crisp queries efficiently for the spatial database applications. The ExMLGF access structure is designed and implemented in a way that database users can have fuzzy queries on both homogenous and heterogeneous domains. In this paper we include a number of algorithms for processing different kinds of queries in spatial databases.