GOLD : a graph oriented language for databases
Ruben Post, Paul M. E. De Bra · TU/e Research Portal · 1993
A simple and powerful graph transformation language for databases is defined whose operations are themselves graphs.It was designed to remedy some of the shortcomings of the GOOD language (see [20]), particularly, its restricted syntax for operations and its dependence on the rather awkward abstraction operator.The new language, GOLD, has only one operation; operations of GOOD are included as special cases.Thanks to a new idea, the core pattern, many more forms of node addition can be specified with this one operation; abstraction becomes superfluous.Due to its capability to add multiple nodes at once, GOLD surpasses GOOD in expressive power: queries are always generic -determinate in the sense of [2] -but they are not restricted to be constructive in the sense of [10J.The simpler forms of the GOLD operation have straightforward interpretations.Instead of imposing syntactic restrictions, the GOLD definition extends the semantics to cover a very broad range of expressions.