Creating and Maintaining Database Links116 Netscape Directory Server Administrator’s Guide • August 2002• ACIs that refer to values of a user’s entry (for example, userattr subject rules)will work if the users is remote.Though access controls are always evaluated on the remote server, you can alsochoose to have them evaluated on both the server containing the database link andthe remote server. This poses several limitations:• During access control evaluation, contents of user entries are not necessarilyavailable (for example, if the access control is evaluated on the servercontaining the database link and the entry is located on a remote server).For performance reasons, clients cannot do remote inquiries and evaluateaccess controls.• The database link does not necessarily have access to the entries beingmodified by the client application.When performing a modify operation, the database link does not have accessto the full entry stored on the remote server. If performing a delete operation,the database link is only aware of the entry’s DN. If an access control specifies aparticular attribute, then a delete operation will fail when being conductedthrough a database link.Advanced Feature: Tuning Database LinkPerformanceThe following sections provide information on tuning the performance of yourdatabase links through connection and thread management. It contains thefollowing parts:• Managing Connections to the Remote Server• Detecting Errors During Normal Processing• Managing Threaded OperationsNOTE By default, access controls set on the server containing the databaselink are not evaluated. To override this default, use thensCheckLocalACI attribute in thecn=database_link_name,cn=chainingdatabase,cn=plugins,cn=config entry. However, evaluatingaccess controls on the server containing the database link is notrecommended unless using cascading chaining.
