The Advanced Information Management Prototype is a system that has been designed and implemented as research vehicle for the area of non-standard database applications. It is an object oriented system heavily influenced by the ideas of nested relations (e.g. NF2, VERSO). The paper addresses the following areas:

Bei relationalen Datenbanksystemen haben sich de-jure-Normen für SQL stetig weiterentwickelt; mit diesen Normen wird es einfacher, portable Datenbankanwendungen zu entwickeln. Die SQL-Norm ruht auf zwei Säulen, zum einen auf der Datenbanksprache SQL, zum anderen auf einer Vorgabe eines Datenbankkatalogs, welcher die gespeicherten Daten beschreiben soll. Im vorliegenden Beitrag wird derjenige Teilbereich des Datenbankkatalogs der aktuellen SQL99-Norm dargestellt, der bereits in der SQL92-Norm (ISO/IEC 9075:1992 bzw. DIN 66315) definiert ist und die klassischen (nicht objektrelationalen) Elemente einer relationalen Datenbank beschreibt. In dieser Darstellung nimmt der zweischichtige Spezifikationsansatz (Informationsschema, Definitionsschema) einigen Raum ein; mit seiner Hilfe weist SQL einen eleganten Weg, auf dem existierende Datenbanksysteme normkonforme Datenbankkataloge bereitstellen können. Anhand des Datenbankmanagementsystems DB2 wird anschließend untersucht, wie ein normkonformer Datenbankkatalog (das sogenannte Informationsschema) „oberhalb” des verfügbaren DB2-Katalogs realisiert werden kann, d. h. wie die vom Informationsschema geforderten Sichten auf DB2-Katalogtabellen abgebildet werden können. Auf generelle Schwierigkeiten und Möglichkeiten einer solchen Abbildung (ein- oder zweistufig) wird ebenso eingegangen wie auf Probleme, die sich speziell bei DB2 ergeben. In einer prototypischen Realisierung konnte das Informationsschema bis auf wenige Einschränkungen komplett umgesetzt werden. Damit wurde die Machbarkeit normkonformer Kataloge nachgewiesen. In heute verfügbaren DBMS-Produkten sind Datenbankkataloge in dieser konsequent normkonformen Gestalt leider immer noch nicht anzutreffen.

Current query languages for relational databases usually are fixed, i.e. they provide only a fixed set of data types and operations. It is usually not possible to extend this set by user defined data types or functions. This is a major drawback especially in advanced applications like engineering applications or office automation. In these areas special data types and special functions are needed quite frequently, e.g. a data type for matrices and a function for matrix multiplication. Since matrices and matrix multiplication are not provided in conventional query languages, the user has to model matrices by low level constructs as, for example, byte strings, and to write a rather cumbersome application program in a conventional programming language for interpreting these byte strings as matrices and for multiplying them. Another example of a missing function is even as simple as the square root function. Therefore, a mechanism is needed that allows the user to define his own data types and functions and add them somehow to the DBMS such that they can be used within the query language in the same way as a normal built-in function on basic data types. This paper describes an extension mechanism for data types and functions that has been implemented at the IBM Scientific Center in Heidelberg. The mechanism is based upon HDBL, an SQL based query language for complex objects. The functions themselves are Permission to copy without fee all or part of this material is granted ~ovided that the copies are not made or distrhted for direct commercial advantage, the VLDB copyright notice Md the title of the publication and its date appear. Imd notice is given chat copying is by permission of the Very Large Data Base Endowment. To copy otherwise. or to republish. raquires a fee and/or special permission from the Endowment.

Because of its small set of data types, the rela-tional model is constrained to simply structured data management tasks. For more advanced applications like engineering databases in the CAD/CAN area even a powerful extension like the NF' model is insufficient , yet: Important concepts like order and duplicates are not supported appropriately, and the free usage of composite items is prohibited by inherent asymmetries. These drawbacks can be removed by a data model which suooorts atomic data, lists, multisets, and tUpleS in"an orthogonal fashion. The necessary operations can be provided in an SQL-like framework. Compared with existing approaches, the expressive power could considerably be increased; nevertheless, the proposed SQL dialect has not become more complicated for comparable tasks, but more consistent and easier to understand.

Recently, extensions for relational database management systems (DBMS) have been proposed to support also hierarchical structures (complex objects). These extensions have been mainly implemented on top of an existing DBMS. Such an approach leads to many disadvantages not only from the conceptual point of view but also from performance aspects. Thus paper reports on a 3-year effort to design and prototype a DBMS to support a generalized relational data model, called extended NF 2 ( N on F irst N ormal F orm) data model which treats flat relations, lists, and hierarchical structures in a uniform way. The logical data model, a language for this model, and alternatives for storage structures to implement generalized relations are presented and discussed.

New applications of DBMS’s in areas of sciences, engineering and offices have produced new requirements that are not satisfied in current DBMS’s. Included among these requirements are support for both the normalized and non-normalized models directly at the system interface level, support for text processing, and support of the temporal domain. To provide these supports, one can try to build additional functions on top of or into an existing DBMS. This approach has been deemed to be inefficient. It is believed that much can be gained by designing a new system to satisfy the new requirements more directly.

Article Free Access Share on Designing DBMS support for the temporal dimension Authors: V Lum View Profile , P Dadam View Profile , R Erbe View Profile , J Guenauer View Profile , P Pistor View Profile , G Walch View Profile , H Werner View Profile , J Woodfill View Profile Authors Info & Claims SIGMOD '84: Proceedings of the 1984 ACM SIGMOD international conference on Management of dataJune 1984 Pages 115–130https://doi.org/10.1145/602259.602276Online:01 June 1984Publication History 81citation418DownloadsMetricsTotal Citations81Total Downloads418Last 12 Months6Last 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

New applications like office information systems need interfaces to data bases which integrate classical data manipulation with management and retrieval of textual (“unformatted”) data. The relational data model is widely accepted as a high level interface to classical (“formatted”) data management. It turns out, however, to be inconvenient for handling even simple data structures as commonly used in information retrieval systems. To attack this shortcoming we propose an extension of the relational model by allowing Non First Normal Form (NF2> relations. We summarize extensions of the relational algebra, with main emphasis on the new “nest” and “unnest” operations which transform between first normal form relations and the NF2 ones. A related language is discussed on the basis of a hypothetical SEQUEL language. As a contribution to the roblem of efficiently supporting the access to NF g tables a novel index support for structured textual data is proposed. It is based on word fragments, words, and word sequences as internal (textual) keys.