Abstract: A distributed data store may maintain versioned hierarchical data structures. Different versions of a hierarchical data structure may be maintained consistent with a transaction log for the hierarchical data structure. When access requests directed to the hierarchical data structure are received, a version of the hierarchical data structure may be identified for processing an access request. For access requests with snapshot isolation, the identified version alone may be sufficient to consistently process the access request. For access requests with higher isolation requirements, such as serializable isolation, transactions based on the access request may be submitted to the transaction log so that access requests resulting in committed transactions may be allowed, whereas access requests resulting in conflicting transactions may be denied.

Abstract: Updates to a hierarchical data structure may be selectively replicated to other replicas of the hierarchical data structure. An update for a hierarchical data structure may be received and committed to the hierarchical data structure. A determination as to whether any other replicas of the hierarchical data structure have permission to receive the update may be made. For those replicas of the hierarchical data structure with permission to receive the update, the update may be provided to the replicas and committed to the replicas. Different types of replication techniques may be implemented, such as pull-based replication techniques or push-based replication techniques. Replication permissions for objects of the hierarchical data structure may be individually defined, in some embodiments.

Abstract: A request is obtained for accessing a resource in a different region from a region indicated by a session token included with the request. The session token is re-encrypted using secret information of the second region. The request to access the resource in the different region can be fulfilled using the re-encrypted session token.

Abstract: Users of a graph data store can access an index object for a graph structure in order to obtain information from objects in the graph data structured index by the index object. A query can be received that is directed to an index object. Links to a subset of data objects in the data store included in the index object can be used to access the subset of data objects to perform the query. In some embodiments, data objects can be manually added or removed from the links included in the index object.

Abstract: A schema for a hierarchical data structure may include application specific extensions to the schema applied to a hierarchical data structure. Class may be added to the schema by individual applications granted access to a hierarchical data structure. When an access request for an object of the hierarchical data structure is received, the class may be identified in the schema and applied to process the access request to the object. Different classes may be added by different applications without disrupting the utilization of the schema for accessing the hierarchical data structure of other applications.

Abstract: Versions of a schema may be maintained for application to hierarchical data structures. Updates to include in a new version of a schema may be received. The updates may be evaluated for compatibility with a current version of the schema. Compatible updates may be included in the new version of the schema. Incompatible updates may not be included in the new version of the schema. The new version of the schema may be made available for application to hierarchical data structures inclusive of the compatible updates to the schema.

Abstract: Updates to a hierarchical data structure may be selectively replicated to other replicas of the hierarchical data structure. An update for a hierarchical data structure may be received and committed to the hierarchical data structure. A determination as to whether any other replicas of the hierarchical data structure have permission to receive the update may be made. For those replicas of the hierarchical data structure with permission to receive the update, the update may be provided to the replicas and committed to the replicas. Different types of replication techniques may be implemented, such as pull-based replication techniques or push-based replication techniques. Replication permissions for objects of the hierarchical data structure may be individually defined, in some embodiments.

Abstract: Updates to a hierarchical data structure may be selectively replicated to other replicas of the hierarchical data structure. An update for a hierarchical data structure may be received and committed to the hierarchical data structure. A determination as to whether any other replicas of the hierarchical data structure have permission to receive the update may be made. For those replicas of the hierarchical data structure with permission to receive the update, the update may be provided to the replicas and committed to the replicas. Different types of replication techniques may be implemented, such as pull-based replication techniques or push-based replication techniques. Replication permissions for objects of the hierarchical data structure may be individually defined, in some embodiments.

Abstract: A distributed data store may maintain versioned hierarchical data structures. Different versions of a hierarchical data structure may be maintained consistent with a transaction log for the hierarchical data structure. When access requests directed to the hierarchical data structure are received, a version of the hierarchical data structure may be identified for processing an access request. For access requests with snapshot isolation, the identified version alone may be sufficient to consistently process the access request. For access requests with higher isolation requirements, such as serializable isolation, transactions based on the access request may be submitted to the transaction log so that access requests resulting in committed transactions may be allowed, whereas access requests resulting in conflicting transactions may be denied.

Abstract: A distributed data store may maintain versioned hierarchical data structures. Different versions of a hierarchical data structure may be maintained consistent with a transaction log for the hierarchical data structure. When access requests directed to the hierarchical data structure are received, a version of the hierarchical data structure may be identified for processing an access request. For access requests with snapshot isolation, the identified version alone may be sufficient to consistently process the access request. For access requests with higher isolation requirements, such as serializable isolation, transactions based on the access request may be submitted to the transaction log so that access requests resulting in committed transactions may be allowed, whereas access requests resulting in conflicting transactions may be denied.

Abstract: Scaling events may be detected for hosting hierarchical data structures. Scaling events may be detected to modify the capacity of a data store for hierarchical data structures to handle changing write workloads, read workloads, or storage capacity. Hierarchical data structures may be moved from one group of storage hosts to another group of storage hosts according to a filtered snapshot that includes the hierarchical data structures to be moved that is provided to the destination storage hosts. Changes made to the hierarchical data structures made at the source storage hosts during the move can be applied to the filtered snapshot so that the hierarchical data structures may be made available at the destination storage hosts inclusive of the changes.

Abstract: A processing device generates an index node for an attribute in a graph database, wherein the index node is linked to a second node by a first edge having a first edge type. The processing device determines a first plurality of additional nodes that have the attribute. For each node of the first plurality of additional nodes, the processing device generates an edge linking the node to the index node, wherein the edge comprises a second edge type.

Abstract: Code may be associated with one or more objects in a hierarchical data structure for execution. An access request for an object in the hierarchical data structure may be received. A schema applicable to the hierarchical data structure may be accessed and evaluated to identify code associated with the object. The code may be executed and servicing of the access request may be performed based, at least in part, on a result of executing the code. Code may be received and stored for inclusion in the schema, in some embodiments. Code may be executed by requesting execution of code that is stored and executed at a remote execution platform, in some embodiments.

Abstract: Versions of a schema may be maintained for application to hierarchical data structures. Updates to include in a new version of a schema may be received. The updates may be evaluated for compatibility with a current version of the schema. Compatible updates may be included in the new version of the schema. Incompatible updates may not be included in the new version of the schema. The new version of the schema may be made available for application to hierarchical data structures inclusive of the compatible updates to the schema.

Abstract: Versions of a schema may be maintained for application to hierarchical data structures. Updates to include in a new version of a schema may be received. The updates may be evaluated for compatibility with a current version of the schema. Compatible updates may be included in the new version of the schema. Incompatible updates may not be included in the new version of the schema. The new version of the schema may be made available for application to hierarchical data structures inclusive of the compatible updates to the schema.

Abstract: A schema for a hierarchical data structure may include application specific extensions to the schema applied to a hierarchical data structure. Class may be added to the schema by individual applications granted access to a hierarchical data structure. When an access request for an object of the hierarchical data structure is received, the class may be identified in the schema and applied to process the access request to the object. Different classes may be added by different applications without disrupting the utilization of the schema for accessing the hierarchical data structure of other applications.

Abstract: A request is obtained for accessing a resource in a different region from a region indicated by a session token included with the request. The session token is re-encrypted using secret information of the second region. The request to access the resource in the different region can be fulfilled using the re-encrypted session token.

Abstract: Updates to a hierarchical data structure may be selectively replicated to other replicas of the hierarchical data structure. An update for a hierarchical data structure may be received and committed to the hierarchical data structure. A determination as to whether any other replicas of the hierarchical data structure have permission to receive the update may be made. For those replicas of the hierarchical data structure with permission to receive the update, the update may be provided to the replicas and committed to the replicas. Different types of replication techniques may be implemented, such as pull-based replication techniques or push-based replication techniques. Replication permissions for objects of the hierarchical data structure may be individually defined, in some embodiments.

Abstract: A schema for a hierarchical data structure may include application specific extensions to the schema applied to a hierarchical data structure. Class may be added to the schema by individual applications granted access to a hierarchical data structure. When an access request for an object of the hierarchical data structure is received, the class may be identified in the schema and applied to process the access request to the object. Different classes may be added by different applications without disrupting the utilization of the schema for accessing the hierarchical data structure of other applications.

Abstract: A request is received by a user in a second region. The request, which is digitally signed with credential associated with the user in the second region causes the generation of a session credential that includes a session key. The user in the second region can use the session credentials to access the resources in the first region.