Service manual

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Chapter 7
Tuning Indexing
As Directory Server handles more and more entries, searches potentially consume
more and more time and system resources. Indexes are one toolto improve search
performance. This chapter covers how Directory Server indexes work so that you
understand the costs and benefits of using a specific index in the context of a
particular deployment.
About Indexes
Indexes associate lookup information with Directory Server entries. Indexes take
the form of files stored with Directory Server databases. A database inthis context is
the physical representation of a suffix. For most deployments, one suffix
correspondsto onedatabase. For somedeployments, onesuffix may be splitacross
multiple databases. Directory Server stores databases under
ServerRoot/slapd-ServerID/db/ by default (the default value of
nsslapd-directory). Here you find individual database instances having one
index file per indexed attribute. For instance, a CN index file for a database,
example, holding entries from the suffix dc=example,dc=com, is called
ServerRoot/slapd-ServerID/db/example/example_cn.db3.
What you index depends upon how client applications access directory data.
Table 7-1 includes short descriptions of standard index types.
Table 7-1 Standard Index Types
Index Type Answers the question...
Approximate Which entries have a value that sounds like foobar for this attribute?
Browsing Which entries fit this virtual list viewsearch?
Equality Which entries have value foobar for this attribute?