Backend Index

Backend Indexes are used to store information that makes it possible to locate entries very quickly when processing search operations.

Indexing is performed on a per-attribute level and different types of indexing may be performed for different kinds of attributes, based on how they are expected to be accessed during search operations.

Dependencies

The following objects have Backend Indexes:

Backend Index Properties

You can use configuration expressions to set property values at startup time. For details, see Property Value Substitution.

Basic Properties Advanced Properties

attribute
confidentiality-enabled
index-extensible-matching-rule
index-type
ttl-age
ttl-enabled

index-entry-limit
substring-length

Basic Properties

Use the --advanced option to access advanced properties.

attribute

Synopsis

Specifies the name of the attribute for which the index is to be maintained.

Default Value

None

Allowed Values

The name of an attribute type defined in the LDAP schema.

Multi-valued

No

Required

Yes

Admin Action Required

None

Advanced

No

Read-Only

Yes

confidentiality-enabled

Synopsis

Specifies whether contents of the index should be confidential.

Description

Setting the flag to true will hash keys for equality type indexes using SHA-1 and encrypt the list of entries matching a substring key for substring indexes.

Default Value

false

Allowed Values

true

false

Multi-valued

No

Required

No

Admin Action Required

None

If the index for the attribute must be protected for security purposes and values for that attribute already exist in the database, the index must be rebuilt before it will be accurate. The property cannot be set on a backend for which confidentiality is not enabled.

Advanced

No

Read-Only

No

index-extensible-matching-rule

Synopsis

The extensible matching rule in an extensible index.

Description

An extensible matching rule must be specified using either LOCALE or OID of the matching rule.

Default Value

No extensible matching rules will be indexed.

Allowed Values

A Locale or an OID.

Multi-valued

Yes

Required

No

Admin Action Required

None

The index must be rebuilt before it will reflect the new value.

Advanced

No

Read-Only

No

index-type

Synopsis

Specifies the type(s) of indexing that should be performed for the associated attribute.

Description

For equality, presence, and substring index types, the associated attribute type must have a corresponding matching rule.

Default Value

None

Allowed Values

  • approximate: This index type is used to improve the efficiency of searches using approximate matching search filters.

  • equality: This index type is used to improve the efficiency of searches using equality search filters.

  • extensible: This index type is used to improve the efficiency of searches using extensible matching search filters.

  • ordering: This index type is used to improve the efficiency of searches using "greater than or equal to" or "less then or equal to" search filters.

  • presence: This index type is used to improve the efficiency of searches using the presence search filters.

  • substring: This index type is used to improve the efficiency of searches using substring search filters.

Multi-valued

Yes

Required

Yes

Admin Action Required

None

If any new index types are added for an attribute, and values for that attribute already exist in the database, the index must be rebuilt before it will be accurate.

Advanced

No

Read-Only

No

ttl-age

Synopsis

The age when timestamps are considered to have expired.

Default Value

0s

Allowed Values

Lower limit: 0 milliseconds.

Multi-valued

No

Required

No

Admin Action Required

None

Advanced

No

Read-Only

No

ttl-enabled

Synopsis

Enable TTL for this generalized time index.

Default Value

false

Allowed Values

true

false

Multi-valued

No

Required

No

Admin Action Required

None

Advanced

No

Read-Only

No

Advanced Properties

Use the --advanced option to access advanced properties.

index-entry-limit

Synopsis

Specifies the maximum number of entries that are allowed to match a given index key before that particular index key is no longer maintained.

Description

This is analogous to the ALL IDs threshold in the Sun Java System Directory Server. If this is specified, its value overrides the JE backend-wide configuration. For no limit, use 0 for the value. Changing the index entry limit significantly can result in serious performance degradation. Please read the documentation before changing this setting.

Default Value

4000

Allowed Values

An integer.

Lower limit: 0.

Upper limit: 2147483647.

Multi-valued

No

Required

No

Admin Action Required

None

If any index keys have already reached this limit, indexes must be rebuilt before they will be allowed to use the new limit.

Advanced

Yes

Read-Only

No

substring-length

Synopsis

The length of substrings in a substring index.

Default Value

6

Allowed Values

An integer.

Lower limit: 3.

Multi-valued

No

Required

No

Admin Action Required

None

The index must be rebuilt before it will reflect the new value.

Advanced

Yes

Read-Only

No