
About Indexes
Chapter 10
Managing Indexes
393
5.
The directory uses the returned entry ID numbers to read the corresponding
entries from the
id2entry.db3
file. The Directory Server then examines each
of the candidate entries to see if any match the search criteria. The directory
returns matching entries to the client as each is found.
The directory continues until either it has examined all candidate entries or it
reaches the limit set in one of the following attributes:
❍
nsslapd-sizelimit
which specifies the maximum number of entries to
return from a search operation. If this limit is reached, the directory returns
any entries it has located that match the search request, as well as an
exceeded size limit error.
❍
nsslapd-timelimit
which specifies the maximum number of seconds
allocated for a search request. If this limit is reached, the directory returns
any entries it has located that match the search request, as well as an
exceeded time limit error.
❍
nsslapd-lookthroughlimit
which specifies the maximum number of
entries that the directory will check when examining candidate entries in
response to a search request.
❍
nsslapd-idlistscanlimit
which specifies the maximum number of
entries in an ID list before the list is considered to equal the entire database.
See
Red Hat Directory Server Configuration, Command, and File Reference
for further
information about these attributes.
idlistscanlimit
When the server uses indexes in the processing of a search operation, it is possible
that one index key matches a large number of entries. For example, consider a
search for
objectclass=inetorgperson
in a directory that contained one million
inetorgperson
entries. When the server reads the
inetorgperson
index key in
the
objectclass
index, it would find one million matching entries. In cases like
this, it is usually more efficient simply to conclude in the index lookup that all the
entries in the database match the query. This causes subsequent search processing
to scan the entire database content, checking each entry as to whether it matches
the search filter. The idea is that the time required to fetch the index keys is not
worthwhile; the search operation is likely to be processed more efficiently by
omitting the index lookup.
Directory Server, then, examines an index, and, if more than a certain number of
entries are found, the server will stop reading the index and mark the search as
unindexed with respect to that particular index. The threshold number of entries is
called the
idlistscanlimit
and is configured with the
Содержание DIRECTORY SERVER 7.1
Страница 1: ...Administrator s Guide Red Hat Directory Server Version7 1 May 2005 Updated February 2009 ...
Страница 20: ...20 Red Hat Directory Server Administrator s Guide May 2005 Glossary 619 Index 635 ...
Страница 22: ...22 Red Hat Directory Server Administrator s Guide May 2005 ...
Страница 26: ...26 Red Hat Directory Server Administrator s Guide May 2005 ...
Страница 78: ...Maintaining Referential Integrity 78 Red Hat Directory Server Administrator s Guide May 2005 ...
Страница 200: ...Assigning Class of Service 200 Red Hat Directory Server Administrator s Guide May 2005 ...
Страница 278: ...Compatibility with Earlier Releases 278 Red Hat Directory Server Administrator s Guide May 2005 ...
Страница 374: ...Troubleshooting Replication Related Problems 374 Red Hat Directory Server Administrator s Guide May 2005 ...
Страница 478: ...Using the Management Information Base 478 Red Hat Directory Server Administrator s Guide May 2005 ...
Страница 488: ...488 Red Hat Directory Server Administrator s Guide May 2005 ...
Страница 528: ...PTA Plug in Syntax Examples 528 Red Hat Directory Server Administrator s Guide May 2005 ...
Страница 545: ...About Windows Sync Chapter 18 Windows Sync 545 Figure 18 1 Active Directory Directory Server Synchronization Process ...
Страница 572: ...572 Red Hat Directory Server Administrator s Guide May 2005 ...
Страница 586: ...Storing Information in Multiple Languages 586 Red Hat Directory Server Administrator s Guide May 2005 ...
Страница 606: ...Searching an Internationalized Directory 606 Red Hat Directory Server Administrator s Guide May 2005 ...
Страница 612: ...Examples of LDAP URLs 612 Red Hat Directory Server Administrator s Guide May 2005 ...
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