article Free Access Share on A non-deterministic deductive database language Author: Yeh-Heng Sheng UniSQL, Inc., 9380 Research Blvd., Kaleido II, Ste. 220, Austin, TX UniSQL, Inc., 9380 Research Blvd., Kaleido II, Ste. 220, Austin, TXView Profile Authors Info & Claims ACM SIGMOD RecordVolume 20Issue 2June 1991pp 188–197https://doi.org/10.1145/119995.115817Published:01 April 1991Publication History 0citation285DownloadsMetricsTotal Citations0Total Downloads285Last 12 Months20Last 6 weeks0 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

The expressive power of pure deductive database languages, such as DATALOG and stratified DATALOGS, is limited in a sense that some useful queries such as functions involving aggregation are not definable in these languages. Our concern in this paper is to provide a uniform logic framework for deductive databases with greater expressive power. It has been shown that with a linear ordering on the domain of the database, the expressive power of some database languages can be enhanced so that some functions involving aggregation can be defined. Yet, a direct implementation of the linear ordering in deductive database languages may seem unintuitive, and may not be very efficient to use in practice. We propose a logic for deductive databases which employs the notion of “identifying each tuple in a relation”. Through the use of these tuple-identifications, different linear orderings are defined as a result. This intuitively explains the reason why our logic has greater expressive power. The proposed logic language is non-deterministu in nature. However, non-determinism is not the real reason for the enhanced expressive power. A deterministic subset of the programs in this language is computational complete in the sense that it defines all the computable deterministic queries. Although the problem of deciding whether a program is in this subset is in general undecidable, we do provide a rather general sufficient test for identifying such programs. Also discussed in this paper is an extended notion of queries which allows both the input and the output of a query to contain interpreted constants of an infinite domain. We show that extended queries involving aggregation can also be defined in the language.