Specifying queries as relational expressions

Boyce, Raymond F.; Chamberlin, Donald D.; Hammer, M. M.; King, William F.

doi:10.1145/951787.951765

Cited by 5 publications

(5 citation statements)

References 4 publications

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“…In TEXPROS, the user's query is specified in terms of an SQL-like form as the structured query language (SQL) of the relational database [3,7,8]. Various critiques of the SQL that point out its strengths and shortcomings can be found in literature [13,17,32,54,55].…”

Section: Discussionmentioning

confidence: 99%

On research issues regarding uncertain query processing in an office document retrieval system

Liu

Wang

1993

Journal of Systems Integration

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Abstract. TEXPROS (TEXt PROcessing System) is an intelligent document processing system; it supports storing, extracting, classifying, categorizing, retrieving, and browsing information from a variety of office documents [76]. This article presents a retrieval subsystem for TEXPROS, which is capable of processing incomplete, imprecise, and vague queries, and providing semantically meaningful responses to the user. The design of the retrieval subsystem is highly integrated with various mechanisms for achieving these goals. First, a system catalog including a thesaurus is used to store the knowledge about the database. Second, there is a query transformation mechanism composed of context construction and algebraic query formulation modules. Given an incomplete or imprecise query, the context construction module searches the system for the required terms and constructs a query that has a complete and precise representation. The resulting query is then formulated into an algebraic expression. Third, in practice, the user may not have a clear idea of what he is searching for. A browsing mechanism is employed for such situations to assist the user in the retrieval process. With the browser, vague queries can be entered into the system until sufficient information is obtained to the extent that the user is able to construct a query for his request. Finally, when processing of queries fails by responding with a null answer to the user, a generalizer mechanism is used to give the user cooperative explanation for the null answer. The presented techniques will contribute to our research toward development of highly intelligent data processing facilities beyond the present scope of database technology.

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Section: Discussionmentioning

confidence: 99%

On research issues regarding uncertain query processing in an office document retrieval system

Liu

Wang

1993

Journal of Systems Integration

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“…QUEL (QUEry Language) has points in common with Data Language/ALPHA [a], SQUARE [3], and SEQUEL [4] in that it is a complete query language which frees the programmer from concern for how data structures are implemented and what algorithms are operating on stored data [9]. As such it facilitates a considerable degree of data independence [24].…”

Section: Quel and The Other Ingres Utility Commandsmentioning

confidence: 99%

The design and implementation of INGRES

Wong

Kreps

Held

2018

Making Databases Work: The Pragmatic Wisdom of Michael Stonebraker

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The currently operational (March 1976) version of the INGRES database management system is described. This multiuser system gives a relational view of data, supports two high level nonprocedural data sublanguages, and runs as a collection of user processes on top of the UNIX operating system for Digital Equipment Corporation PDP 11/40, 11/45, and 11/70 computers. Emphasis is on the design decisions and tradeoffs related to (1) structuring the system into processes, (2) embedding one command language in a general purpose programming language, (3) the algorithms implemented to process interactions, (4) the access methods implemented, (5) the concurrency and recovery control currently provided, and (6) the data structures used for system catalogs and the role of the database administrator. Also discussed are (1) support for integrity constraints (which is only partly operational), (2) the not yet supported features concerning views and protection, and (3) future plans concerning the system.

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“…An algebra or calculus is relationally complete if, given any finite collection of relations R 1 , R 2 , …, R N in normal form, the expressions of the algebra or calculus permit definition of any relation definable from R 1 , R 2 , …, R N by alpha expressions [7]. A relational database language SQL (Structured Query Language) based on the relational algebra and calculus was proposed [1,2,3,4].…”

Section: Introductionmentioning

confidence: 99%