GSQL-R: A query language supporting raster data

Spatial database has become the dominant techniques to manage spatial data in geographical information systems, and geographic structured query language (GSQL) is the key of spatial database design and implementation. At present, GSQL for vector data has been widely studied. However, when the raster data are considered, there is little specific research. On the basis of corresponding ADTs (abstract data type), the GSQL-R is defined and the instances are described. The definition includes three parts, i.e., data definition language, data table schema and data manipulation language. The example statements of GSQL-R demonstrate that it provides a convenient way for raster data access and manipulation and supports vector data seamlessly