Skip to main content Accessibility help
×
Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-09T16:30:02.274Z Has data issue: false hasContentIssue false

Chapter 4 - Meta-Information

Published online by Cambridge University Press:  07 September 2010

Henry Balen
Affiliation:
Xenotrope Inc.
Get access

Summary

Meta-information is information about information. Now you have the definition, what does this actually imply for computational systems? There are occasions where you naturally make use of meta-information: the schema of your database, directory services, information about a system's configuration, and so forth. Meta-information in each of these cases allows us to increase the flexibility of the system. For example, if the schema for a database is embedded within your application, then you have negated any possible reuse of the information in the database. Separating the schema from the application allows other applications to make use of the same information.

The more flexible our systems are, the greater the chance of survival they have in the ever-changing environment of the modern computing system. To be flexible, you need to support dynamic discovery and incorporate new services when they become available. The key to providing flexible systems lies in the amount of self-description within the system. Some programming languages support such self-description (a good example is reflection in Java). There is also support for dynamic discovery of objects and meta-information within CORBA. In this chapter we will explore why meta-information provides such flexibility and how existing facilities can provide meta-information.

A lot of work done has been done in the past couple of decades on reflection in object-oriented systems. Reflection is the ability of a system of objects to reason about itself.

Type
Chapter
Information
Publisher: Cambridge University Press
Print publication year: 2000

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Save book to Kindle

To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×