A constrant-based spatial extension to SQL
Gabriel M. Kuper, Sridhar Ramaswamy, Kyuseok Shim, Jianwen Su · 1998
The con~traint database model provides a uniform framework for handling spatial and non-spatial data.We describe our proposal for a query language for GISS based on this model.Our language is called CSQL, as it is based on SQL.CSQL provides the full query capabilities of SQL on the non-spatial part of the database while being tightly integrated with the spatial part.This allows us to optimize C!SQL queries in a unified fashion, considering both the spatial amdnon-spatial attributes simultaneously.TtTeare in the process of implementing a constraint database system using CSQL as a query language, via a relational algebra CALG, and an e~tensible database system.