About Knowledge References82 Netscape Directory Server Deployment Guide • December 2001About Knowledge ReferencesOnce you have distributed your data over several databases, you need to define therelationship between the distributed data. You do this using knowledge references,pointers to directory information held in different databases. The Directory Serverprovides the following types of knowledge references to help you link yourdistributed data into a single directory tree:• Referrals—The server returns a piece of information to the client applicationindicating that the client application needs to contact another server to fulfillthe request.• Chaining—The server contacts other servers on behalf of the client applicationand returns the combined results to the client application after finishing theoperation.The following sections describe and compare these two types of knowledgereferences in more detail.Using ReferralsA referral is a piece of information returned by a server that tells a clientapplication the server to contact to proceed with an operation request. Thisredirection mechanism occurs when a client application requests a directory entrythat does not exist on the local server.Directory Server supports two types of referrals:• A default referralThe directory returns a default referral when a client application presents a DNfor which the server does not have a matching suffix. Default referrals arestored in the configuration file of the server. You can set a default referral forthe directory server and a separate default referral for each database.The default referral you set for each database is done through the suffixconfiguration information. When the suffix of the database is disabled, you canconfigure the directory to return a default referral to client requests made tothat suffix. For more information about suffixes, refer to “About Suffixes,” onpage 80. For information on configuring suffixes, refer to Netscape DirectoryServer Administrator’s Guide.
