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Relational Data Base Machines

IP.com Disclosure Number: IPCOM000131377D
Original Publication Date: 1979-Mar-01
Included in the Prior Art Database: 2005-Nov-10
Document File: 15 page(s) / 54K

Publishing Venue

Software Patent Institute

Related People

Diane C.P. Smith: AUTHOR [+4]

Abstract

University of New Mexico* [Figure containing following caption omitted: Relational data base machines using head-per- track disk technology or its electronic equivalent can move processing logic closer to the data, providing simplified storage organizations for large-scale applications.] The potential of special-purpose hardware, particularly intelligent secondary storage devices, holds special appeal to the implementers of relational data base management systems. The relational model, however, is structurally and behaviorally far removed from the storage organization and primitive operators of existing hardware. This means that the implementer must construct multiple levels of sophisticated software to produce an efficient system. The development of VLSI technology for chip design and innovations in mass storage technology suggest that this gap can be narrowed, easing the problem of providing efficient support for high-level, user-oriented data base management systems. The designs proposed for relational DBMS support have been investigated and developed to very different degrees. Some have been specified for only a partial set of DBMS functions; some have been simulated while others have been prototyped. The depth of coverage in this survey reflects these differences and also the availability of published documentation. Because of variations in the design objectives and in the detail of specifications, no attempt is made to contrast critically the expected performance.

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THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

This record contains textual material that is copyright ©; 1979 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Contact the IEEE Computer Society http://www.computer.org/ (714-821-8380) for copies of the complete work that was the source of this textual material and for all use beyond that as a record from the SPI Database.

Relational Data Base Machines

Diane C.P. Smith

John Miles Smith

University of New Mexico*

  (Image Omitted: Relational data base machines using head-per- track disk technology or its electronic equivalent can move processing logic closer to the data, providing simplified storage organizations for large-scale applications.)

The potential of special-purpose hardware, particularly intelligent secondary storage devices, holds special appeal to the implementers of relational data base management systems. The relational model, however, is structurally and behaviorally far removed from the storage organization and primitive operators of existing hardware. This means that the implementer must construct multiple levels of sophisticated software to produce an efficient system. The development of VLSI technology for chip design and innovations in mass storage technology suggest that this gap can be narrowed, easing the problem of providing efficient support for high-level, user-oriented data base management systems.

The designs proposed for relational DBMS support have been investigated and developed to very different degrees. Some have been specified for only a partial set of DBMS functions; some have been simulated while others have been prototyped. The depth of coverage in this survey reflects these differences and also the availability of published documentation. Because of variations in the design objectives and in the detail of specifications, no attempt is made to contrast critically the expected performance.

The relational model

The relational model is based on the notion that objects can be modeled as wary relations. For example, a "supplier" can be thought of as a relationship among such attributes as "supplier number'' (S#), "supplier name'' (SN) and "supplier location'' (SLOC). Such relations can be pictured as unordered tables with nonredundant rows.

1

Figure 1 shows a relational model of a simplified inventory data base. Individual rows in the PART table correspond to individual types of parts in the inventory. Because rows are required to be nonredundant within a relation, each row can be named uniquely by a subset of its attributes. For

example, in Figure 1 either S# or SN can be used to name a row uniquely, while S# and P# must be used together to identify a row of the SUPPLY table. Such sets of attributes are called the key of the relation. If a subset of the attributes in one relation is the key of a second relation, we can interpret the first relation as a relationship between its remaining attributes and...