The computational completeness of extended database query languages

The computational completeness is demonstrated of certain extended database query languages, namely, POSTGRES and GENESIS, and a language defined by A. Aho and J. Ullman (1979). The method used is to implement a Turing machine interpreter in each of the languages. These query languages were defined as extensions to traditional database languages in order to encompass certain specific new applications. Results show that these extensions have already encompassed all the computational power of any programming language.<
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