--- title: Backend Index description: Backend Indexes are used to store information that makes it possible to locate entries very quickly when processing search operations. component: pingds version: 8.1 page_id: pingds:configref:objects-backend-index canonical_url: https://docs.pingidentity.com/pingds/8.1/configref/objects-backend-index.html section_ids: dependencies: Dependencies backend_index_properties: Backend Index properties basic_properties: Basic properties attribute: attribute big-index-extensible-matching-rule: big-index-extensible-matching-rule big-index-included-attribute-value: big-index-included-attribute-value confidentiality-enabled: confidentiality-enabled index-extensible-matching-rule: index-extensible-matching-rule index-type: index-type ttl-age: ttl-age ttl-enabled: ttl-enabled advanced_properties: Advanced properties index-entry-limit: index-entry-limit substring-length: substring-length --- # 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 depend on Backend Indexes: * [Pluggable Backend](objects-pluggable-backend.html) ## Backend Index properties You can use configuration expressions to set property values at startup time. For details, see [Property value substitution](expressions.html). | Basic Properties | Advanced Properties | | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------- | | [attribute](#attribute) [big-index-extensible-matching-rule](#big-index-extensible-matching-rule) [big-index-included-attribute-value](#big-index-included-attribute-value) [confidentiality-enabled](#confidentiality-enabled) [index-extensible-matching-rule](#index-extensible-matching-rule) [index-type](#index-type) [ttl-age](#ttl-age) [ttl-enabled](#ttl-enabled) | [index-entry-limit](#index-entry-limit) [substring-length](#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 | ### big-index-extensible-matching-rule | | | | ----------------------- | ---------------------------------------------------------------------------------------------- | | *Synopsis* | The extensible matching rule in a big index. | | *Description* | An extensible matching rule must be specified using either LOCALE or OID of the matching rule. | | *Default value* | No big index extensible matching rules will be indexed. | | *Allowed values* | A Locale or an OID. | | *Multi-valued* | Yes | | *Required* | No | | *Admin action required* | NoneThe index must be rebuilt before it will reflect the new value. | | *Advanced* | No | | *Read-only* | No | ### big-index-included-attribute-value | | | | ----------------------- | -------------------------------------------------------------------------------------------------------------- | | *Synopsis* | An attribute value which should be indexed in any big indexes. | | *Description* | Restricts the set of attribute values indexed by big indexes. All attribute values will be indexed by default. | | *Default value* | All attribute values will be indexed. | | *Allowed values* | A string. | | *Multi-valued* | Yes | | *Required* | No | | *Admin action required* | NoneThe index must be rebuilt before it will reflect the new attribute value(s). | | *Advanced* | No | | *Read-only* | No | ### 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* | truefalse | | *Multi-valued* | No | | *Required* | No | | *Admin action required* | NoneIf 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* | NoneThe 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. * big-equality: This index type is used to perform efficient equality filter queries against attributes with few unique values. * big-extensible: This index type is used to improve the efficiency of searches using extensible matching rule search filters against attributes with few unique values. * 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* | NoneIf 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* | After reaching the time of the indexed attribute plus this age, PingDS considers the entry expired and ready for deletion. Use a low setting to quickly delete entries with expiration timestamps, for example, with coreTokenExpirationDate. Use a high setting to delay deleting entries with "last use" timestamps, for example, with lastLoginTime. | | *Default value* | 0s | | *Allowed values* | Uses [duration syntax](duration-syntax.html).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* | truefalse | | *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* | NoneIf 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* | NoneThe index must be rebuilt before it will reflect the new value. | | *Advanced* | Yes | | *Read-only* | No |