A Generalized Approach to Collections, Tables, and Other Intensional/Extensional Constructs

William Kent
Database Technology Department
Hewlett-Packard Laboratories
Palo Alto, California

Nov 1993

SQL3 Discussion Paper
ANSI Number: X3H2-93-371r1
Nov. 21, 1993
Title: A Generalized Approach to Collections, Tables, and Other Intensional/Extensional Constructs
Author: William Kent

References:

1 X3H2-93-359R/ISO DBL MUN-003, (ISO-ANSI Working Draft) Database Language SQL (SQL3), Jim Melton (ed.), August 1993.

2 X3H2-93-371, "Sets and Other Collections", July 30, 1993, by William Kent.

3 William Kent, "Carriers and Cargos: A General Paradigm for Modeling Collections, Tables, Multimedia, Spatial Constructs, and Other Intensional/Extensional Objects", Nov. 21, 1993 (draft). [html]

1 STATUS NOTE

This is an expanded version of [2], exploring the topic in greater detail as well as extending underlying concepts to related topics.

2 DISCUSSION

This paper seeks to establish consensus on basic principles underlying sets and other collections in SQL3 [1], and to generalize these principles to other related areas. Details are described in the attached paper [3]. Key objectives:

Recognize and articulate the distinction between intensional and extensional collections.
Recognize a similar intensional/extensional distinction in other areas such as documents, files, spatial and geometric constructs, multi-media, large objects, events, and even tables.
Develop a carrier/cargo paradigm which captures the general characteristics of intensional and extensional objects, which can then be applied to these various areas.

3 ACTION PROPOSED

Discuss [3] in order to determine and establish consensus on the various points therein.
Document the resulting consensus positions as definitions and concepts in [1].
Develop appropriate change proposals or language opportunities in [1].