--- title: Schema Backend description: The Schema Backend provides access to the directory server schema information, including the attribute types, object classes, attribute syntaxes, matching rules, matching rule uses, DIT content rules, and DIT structure rules that it contains. component: pingds version: 8.1 page_id: pingds:configref:objects-schema-backend canonical_url: https://docs.pingidentity.com/pingds/8.1/configref/objects-schema-backend.html section_ids: parent: Parent schema_backend_properties: Schema Backend properties basic_properties: Basic properties backend-id: backend-id enabled: enabled show-all-attributes: show-all-attributes writability-mode: writability-mode advanced_properties: Advanced properties java-class: java-class schema-entry-dn: schema-entry-dn --- # Schema Backend The Schema Backend provides access to the directory server schema information, including the attribute types, object classes, attribute syntaxes, matching rules, matching rule uses, DIT content rules, and DIT structure rules that it contains. The server allows "modify" operations in this backend to alter the server schema definitions. The configuration entry for this backend is based on the ds-cfg-schema-backend structural object class. Note that any attribute types included in this entry that are not included in this object class (or the parent ds-cfg-backend class) appears directly in the schema entry. ## Parent The Schema Backend object inherits from [Local Backend](objects-local-backend.html). ## Schema Backend 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 | | ------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------- | | [backend-id](#backend-id) [enabled](#enabled) [show-all-attributes](#show-all-attributes) [writability-mode](#writability-mode) | [java-class](#java-class) [schema-entry-dn](#schema-entry-dn) | ### Basic properties Use the `--advanced` option to access advanced properties. ### backend-id | | | | ----------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | *Synopsis* | Specifies a name to identify the associated backend. | | *Description* | The name must be unique among all backends in the server. The backend ID may not be altered after the backend is created in the server. | | *Default value* | None | | *Allowed values* | A string. | | *Multi-valued* | No | | *Required* | Yes | | *Admin action required* | NoneNo base entry has been created as part of this process. A base entry needs to be created before adding further entries to the backend. Please refer to the documentation to create a base entry. | | *Advanced* | No | | *Read-only* | Yes | ### enabled | | | | ----------------------- | --------------------------------------------------------------------------------------------- | | *Synopsis* | Indicates whether the backend is enabled in the server. | | *Description* | If a backend is not enabled, then its contents are not accessible when processing operations. | | *Default value* | None | | *Allowed values* | truefalse | | *Multi-valued* | No | | *Required* | Yes | | *Admin action required* | None | | *Advanced* | No | | *Read-only* | No | ### show-all-attributes | | | | ----------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | *Synopsis* | Indicates whether to treat all attributes in the schema entry as if they were user attributes regardless of their configuration. | | *Description* | This may provide compatibility with some applications that expect schema attributes like attributeTypes and objectClasses to be included by default even if they are not requested. Note that the ldapSyntaxes attribute is always treated as operational in order to avoid problems with attempts to modify the schema over protocol. | | *Default value* | None | | *Allowed values* | truefalse | | *Multi-valued* | No | | *Required* | Yes | | *Admin action required* | None | | *Advanced* | No | | *Read-only* | No | ### writability-mode | | | | ----------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | *Synopsis* | Specifies the behavior that the backend should use when processing write operations. | | *Default value* | enabled | | *Allowed values* | * disabled: Causes all write attempts to fail. * enabled: Allows write operations to be performed in that backend (if the requested operation is valid, the user has permission to perform the operation, the backend supports that type of write operation, and the global writability-mode property is also enabled). * internal-only: Causes external write attempts to fail but allows writes by replication and internal operations. | | *Multi-valued* | No | | *Required* | Yes | | *Admin action required* | None | | *Advanced* | No | | *Read-only* | No | ## Advanced properties Use the `--advanced` option to access advanced properties. ### java-class | | | | ----------------------- | ---------------------------------------------------------------------------------------------- | | *Synopsis* | Specifies the fully-qualified name of the Java class that provides the backend implementation. | | *Default value* | org.opends.server.backends.SchemaBackend | | *Allowed values* | A Java class that extends or implements:- org.opends.server.api.Backend | | *Multi-valued* | No | | *Required* | Yes | | *Admin action required* | The object must be disabled and re-enabled for changes to take effect. | | *Advanced* | Yes | | *Read-only* | No | ### schema-entry-dn | | | | ----------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | *Synopsis* | Defines the base DNs of the subtrees in which the schema information is published in addition to the value included in the base-dn property. | | *Description* | The value provided in the base-dn property is the only one that appears in the subschemaSubentry operational attribute of the server's root DSE (which is necessary because that is a single-valued attribute) and as a virtual attribute in other entries. The schema-entry-dn attribute may be used to make the schema information available in other locations to accommodate certain client applications that have been hard-coded to expect the schema to reside in a specific location. | | *Default value* | cn=schema | | *Allowed values* | A valid DN. | | *Multi-valued* | Yes | | *Required* | No | | *Admin action required* | None | | *Advanced* | Yes | | *Read-only* | No |