Netscape NETSCAPE DIRECTORY SERVER 6.1 - ADMINISTRATOR, Administrator'S Manual

Page: 351 / 578

About Indexes
Chapter 10 Managing Indexes 351
Overview of Standard Indexes
Because of the need to maintain default indexes and other internal indexing
mechanisms, the Directory Server also maintains certain standard index files. The
following standard indexes exist by default, and you do not need to generate them:
•
id2entry.db3
—contains the actual directory database entries. All other
database files can be recreated from this one.
•
id2children.db3
—restricts the scope of one-level searches, that is, searches
that examine an entry’s immediate children.
•
dn.db3
—controls the scope of subtree searches; that is, searches that examine
an entry and all the entries in the subtree beneath it.
•
dn2id.db3
—begins all searches efficiently by mapping an entry’s
distinguished name to its ID number.
Overview of the Searching Algorithm
Indexes are used to speed up searches. To understand how the directory uses
indexes, it helps to understand the searching algorithm. Each index contains a list
of attributes (such as the
cn
, common name, attribute) and a pointer to the entries
corresponding to each value. Directory Server processes a search request as
follows:
1.
An LDAP client application, such as Netscape Communicator or Directory
Server Gateway sends a search request to the directory.
dnComp
X Used to help accelerate subtree searches in the
directory.
objectClass
X Used to help accelerate subtree searches in the
directory.
entryDN
X Speeds up entry retrieval based on DN searches.
parentID
X Enhances directory performance during one-level
searches.
numSubordinates
X Used by the Directory Server Console to enhance
display performance on the Directory tab.
nsUniqueID
X Used to search for specific entries.
Table 10-2
System indexes (Continued)
Attribute Eq Pres Purpose