Methods and apparatus for generating and using safe constraint queries

摘要

Methods and apparatus are provided for ensuring that queries presented to a database are safe thus providing solutions to both undecidability and lack of effective syntax issues. In a one aspect of the invention, a method for use in a database system includes obtaining an original query entered by a user. The invention then provides for pre-processing the query before submittal to a database engine associated with the database system wherein a result of the pre-processing operation is to ensure that a query provided to the engine is safe. Safety has a different meaning depending on the application. For example, safety may include ensuring that a query will return an output with finite results or it may include ensuring that certain geometric properties in the query are preserved in the output.