Idlistscanlimit - Red Hat DIRECTORY SERVER 7.1 - ADMINISTRATOR Administrator's Manual

The directory uses the returned entry ID numbers to read the corresponding
5.
entries from the
id2entry.db3
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
H
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
H
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
H
entries that the directory will check when examining candidate entries in
response to a search request.
nsslapd-idlistscanlimit
H
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
entries. When the server reads the
inetorgperson
the index, it would find one million matching entries. In cases like
objectclass
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
file. The Directory Server then examines each
which specifies the maximum number of entries to
which specifies the maximum number of seconds
which specifies the maximum number of
which specifies the maximum number of
in a directory that contained one million
and is configured with the
index key in
inetorgperson
Chapter 10 Managing Indexes
About Indexes
393