Metadata Working Group
Working Group Projects
ISO/IEC JTC 1 / SC 32 / WG 02
DRAFT
Metadata Query Service
An Object Technology Extensions to the
ISO/IEC 11179 Specification and Standardization of Data Elements, Part 3, Basic Attributes. (BNE 027)
MetaData Query Service
Abstract
This standard specifies the behavioral aspects of a data registry. The behavior is stated in the form of an interface specification better known as a Metadata Query Service. The Metadata Query Service provides a way to access the information in a data registry in a well-defined way.
This standard will be of interest to information managers, data administrators, and others who are responsible for making data shareable. It will also be of particular interest to manufacturers of repository and CASE tool products.
Notice:
This is a draft proposed International Organization for Standardization (ISO). As such, this is not a completed standard. The Technical Committee may modify this document as a result of comments received during public review and its approval as a standard.
Permission is granted to members of NCITS, its technical committees, and their associated task groups to reproduce this document for the purposes of NCITS standardization activities without further permission, provided this notice is included. All other rights are reserved. Any commercial or for-profit reproduction is strictly prohibited.
Contents
History
Preface
Discussion
Foreword
1. Scope, purpose, and application
3. Definitions
4. Introduction
5. Requirements
6. Use-Cases
7. Model
8. Interface
9. Conformance
10. Extensibility
History
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Initial Draft 1 |
20 May 1998 |
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The initial draft of the Metadata Query Service to the ISO/IEC 11179 Specification and Standardization of Data Elements, Part 3, Basic Attributes. It is intended to provide some basis for further development of the extension. This is proposed for discussion at the SC 32/WG 2 meeting to be held on July 6-11, 1998 in Brisbane, Australia. |
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Preface
This draft is in response to a New Work Item as discussed in the National Committee for Information Technology Standards (NCITS) L8, Data Representation, Special Interest Group held at the Hunt's Landing Best Western, Pennsylvania May 13-15, 1998.
Contact Points
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Thomas C. Culpepper |
Harold R. Solbrig |
Supporting Organizations
The following organizations have been involved in the process of developing, prototyping and/or reviewing this draft. The submitters of this draft thank them for participating and giving their valuable input.
Acknowledgements
The following individuals have been involved in the process of developing and/or reviewing this draft. The submitters of this draft thank them for participating, and giving their valuable input. Ultimately, the ideas expressed in the document are those of the authors and do not necessarily reflect the views or ideas of these individuals, nor does the inclusion of their names imply their endorsement of the final submission.
Proof of Concept
It is proposed that a prototype be developed to reflect the viability of the Metadata Query Service.
Discussion
There are a number of issues to be considered in developing the Metadata Query Service. The editors of this draft are just starting the consensus process on many of these issues. The areas of concern are outlined below and will evolve as this draft evolves.
Outline:
- Identify things that need to be done prior to beginning work on this standard.
- Solicit and document requirements.
- Solicit and document use-cases.
- Use class modeling to define the business objects and application architecture.
- Create object instances of these classes to reveal how the classes interoperate dynamically.
Things that need to be done prior to beginning work on this standard:
Editors and Contributors
A composite list of editors and/or contributors to this standard have not yet been fully identified. It is anticipated that they may come from different backgrounds and will work together to integrate their different perspectives into a flexible framework that affords interoperability and extensibility. A complete list needs to be identified.
Identification of patterns for use with this standard:
Previous Work
It is anticipated that much of the work done in the Lexicon Query Service (LQS) will be used as a pattern for the Metadata Query Service.
The Lexicon "L" portion of the LQS deals with terminology and the underlining terminology model which will need to be reviewed and coordinated with the ISO/IEC 11179 Specification and Standardization of Data Elements, Part 3, Basic Attributes along with the Committee Draft (CD) for INTERNATIONAL STANDARD ISO/IEC 14481- Information technology (IT) Conceptual schema modeling facilities (CSMF).
The Query Service "QS" portion of the LQS deals with access information in a well-defined way. It is anticipated that the "QS" portion be used as the pattern for accessing metadata from a data registry.
Things that need to be done in parallel with this standard:
Extensions to the ISO/IEC 11179
At the NCITS L8, Data Representation, Special Interest Group held at the Hunt's Landing Best Western, Pennsylvania May 13-15, 1998 several extensions to the ISO/IEC 11179 were discussed. These include, coverage of data composites and other complex data, extensions to better handle terminology/classification metadata, and the addition of attributes needed to document data element groups and to document application level data. As these extensions move forward there should exist coordination and/or usage betweem them and this extension.
Investigation into existing standards
It is anticipated that further investigation be done with existing standards.
1. OMG
BOCA
The Business Object Component Architecture (BOCA) is in the process of being adopted as an OMG specification.
CDL
The Component Definition Language (CDL) it also includes an extension to Interface Definition Language (IDL).
Interface Repository IDL
Review the IDL to the Interface Repository. Possible patterns for access may be gleaned.
MOF
The Meta Objects Facility.
2. XML
The eXtended Markup Language (XML) is gaining wide support as a flexible format for describing highly structured information (documents). HL7 is looking into using XML as a format for healthcare content. Tools are being developed for XML, and popular web browsers are expected to support XML shortly.
Some people are using XML on the server side and others on the client side. On the server side, XML databases are being developed for storing XML documents. Advances in XML databases are expected as they are becoming popular. XML is being used on the client side in ways similar to web pages being displayed in web browsers. Since XML is a more general form than HTML, style sheets can be used to map XML contents into different user views.
While XML is gaining ground, it is not clear if XML support needs to be defined in this standard and should be discussed further.
Things that need to be included in this draft for final approval:
Requirements
A set of mandatory and optional requirements will be identified to ensure usage of this standard. They will be included in Section 6 of this draft. These may come from the editors, contributors, and/or outside bodies. The solicitation of input should go through the necessary channels as outlined by the American National Standard for Information Technology if such a channel exists.
Use-Cases
Metadata Query Services may be used by many kinds of systems and for many purposes. It is intended that use-cases be included in Section 5 of this draft to assist in understanding the variety of patterns of usage. These use-cases will be used to capture the functional requirements and allow the mapping of them to the object model.
Model
Interface Specification
This is the actual IDL definitions.
Conformance
It may be necessary to provide levels of conformance to this standard in an effort to allow greater usage of the standard.
Extensibility
Things that should be discussed as potentially being included in this standard:
Componentization
In order to manage optional requirements, a base component should be utilized that indicates which interfaces have been implemented. The component must also have a mechanism to traverse to those interfaces that are implemented.
Other component architectures have existed, such as in COM/OLE and Java Beans. The OMG is in the process of defining a standard component model that is expected to be finished in the summer of 1998. This draft will consider that OMG Component Model if it becomes standardized in time.
Constraint Languages
When developing query mechanisms it sometimes requires the ability to provide constraints on the access. If this is deemed necessary, a constraint language may need to be considered.
1. Scope, purpose, and application
1.1 Scope
This is an extension to the ISO/IEC 11179 Specification and Standardization of Data Elements, Part 3, Basic Attributes. The the ISO/IEC 11179 Specification and Standardization of Data Elements, Part 3, Basic Attributes deals with the schema of a data registry where the descriptions of shareable data is stored. The Metadata Query Service is scoped at the level of accessing the descriptive information that is considered "metadata".
1.2 Purpose
The purpose of the Metadata Query Service is to provide Electronic Data Interchange (EDI) data element designers', software engineers, and end-users a well-defined standard way of accessing metadata from a data registry in order to curtail proprietary solutions and move to better solutions for Distributed Object Computing (DOC).
1.3 Application
The the ISO/IEC 11179 Specification and Standardization of Data Elements, Part 3, Basic Attributes defines the schema of a data registry, it can be used by a data registry management system in structuring a data registry. The Metadata Query Service will provide the necessary run-time access to the data registry. This run-time access can be used to build applications on the fly, assist in data validation, and assist in mediating data across disparate systems.
2. Normative references
The following standards contain provisions that, through reference in this text, constitute provisions of this American National Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this American National Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.
ISO/IEC DIS 11179-1, Information technology - Specification and standardization of data elements - Framework for the specification and standardization of data elements
ISO/IEC DIS 11179-2, Information technology - Specification and standardization of data elements - Classification for data elements
ISO/IEC 11179-3:1994, Information technology - Specification and standardization of data elements - Basic attributes of data elements
ISO/IEC 11179-4:1995, Information technology - Specification and standardization of data elements - Rules and guidelines for the formulation of data definitions
ISO/IEC 11179-5:1995, Information technology - Specification and standardization of data elements Naming and identification principles for data elements
ISO/IEC 11179-6:1997, Information technology - Specification and standardization of data elements - Registration of data elements
3. Definitions
4. Introduction
5. Requirements
Mandatory Requirements
Need to be identified.
Optional Requirements
<DD
Need to be identified.
Discussion Points Requested
<DD
Need to be identified.
6. Use-Cases
Need to be identified.
7. Model
8. Interface Specification
9. Conformance
10. Extensibility
