Indexing rules

Index rules attached to attributes make it possible to retrieve information faster. If only the attribute is given, no indexes are maintained. Directory Server provides the following indexing rules:

• Equality
• Ordering
• Approximate
• Substring
• Reverse

Indexing rules specifications for attributes

Specifying an indexing rule for an attribute controls the creation and maintenance of special indexes on the attribute values. This greatly improves the response time to searches with filters which include those attributes. The five possible types of indexing rules are related to the operations applied in the search filter.

Equality

Applies to the following search operations:

• equalityMatch '='

For example:

"cn = John Doe"

Ordering

Applies to the following search operation:

• greaterOrEqual '>='
• lessOrEqual '<='

For example:

"sn >= Doe"

Approximate

Applies to the following search operation:

• approxMatch '~='

For example:

"sn ~= doe"

Substring

Applies to the search operation using the substring syntax:

• substring '*'

For example:

"sn = McC*"
"cn = J*Doe"

Reverse

Applies to the following search operation:

• '*' substring

For example:

"sn = *baugh"

At a minimum, it is recommended that you specify equal indexing on any attributes that are to be used in search filters.