Using Indexes To Improve Database Performance - Red Hat DIRECTORY SERVER 8.1 - DEPLOYMENT Deployment Manual

Figure 5.13. Authenticating a Client and Retrieving Data Using Different Servers
In this illustration, the following steps are performed:
1. The client application binds with Server A, and Server A tries to confirm that the user name and
password are correct.
2. Server A does not contain an entry corresponding to the client application. Instead, it contains
a database link to Server B, which contains the actual entry of the client. Server A sends a bind
request to Server B.
3. Server B sends an acceptance response to Server A.
4. Server A then processes the client application's request using another database link. The
database link contacts a remote data store located on Server C to process the search operation.
Unsupported Access Controls
Database links do not support the following access controls:
• Controls that must access the content of the user entry are not supported when the user entry is
located on a different server. This includes access controls based on groups, filters, and roles.
• Controls based on client IP addresses or DNS domains may be denied. This is because the
database link impersonates the client when it contacts remote servers. If the remote database
contains IP-based access controls, it evaluates them using the database link's domain rather than
the original client domain.

5.4. Using Indexes to Improve Database Performance

Searches performed by client applications can be time and resource intensive, depending on the size
of the databases. To help alleviate this problem, use indexes to improve search performance.
Indexes are files stored in the directory databases. Separate index files are maintained for each
database in the directory service. Each file is named according to the attribute it indexes. The index
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