Abstract: The updating of a definition layer or schema for a large distributed database can be accomplished using a plurality of data store tiers. A distributed database can be made up of many individual data stores, and these data stores can be allocated across a set of tiers based on business logic or other allocation criteria. The update can be applied sequentially to the individual tiers, such that only data stores for a single tier are being updated at any given time. This can help to minimize downtime for the database as a whole, and can help to minimize problems that may result from an unsuccessful update. Such an approach can also allow for simplified error detection and rollback, as well as providing control over a rate at which the update is applied to the various data stores of the distributed database.

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: Service interruptions in a multi-tenancy, network-based storage system can be mitigated by constraining the execution of queries. In various examples, a network-based storage system may receive a request to execute a query against data maintained by the network-based storage system. The network-based storage system may perform a unit of work to execute the query, progressing through some, but not all, of a set of operations that are to be completed for completing execution of the query. Upon completion of the unit of work, query execution may be paused, query state data may be saved, and query results may be generated for consumption by the requesting computing device. In some embodiments, tokens that are usable to resume query execution based on the saved query state data may be sent to customer computing devices for resuming query execution on-demand.

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: Techniques for implementing conflict-free replicated data types in a database are described. A first database replica of a database hosted by a provider network receives an identifier of a first operation to perform on an element stored in the database, the element being of a conflict-free replicated data type. A second database replica of the database receives an identifier of a second operation to perform on the element. The second operation is determined to not conflict with the first operation. The first operation and the second operation are performed on the element stored by the first database replica. The first operation and the second operation are performed on the element stored by the second database replica.

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: Service interruptions in a multi-tenancy, network-based storage system can be mitigated by constraining the execution of queries. In various examples, a network-based storage system may receive a request to execute a query against data maintained by the network-based storage system. The network-based storage system may perform a unit of work to execute the query, progressing through some, but not all, of a set of operations that are to be completed for completing execution of the query. Upon completion of the unit of work, query execution may be paused, query state data may be saved, and query results may be generated for consumption by the requesting computing device. In some embodiments, tokens that are usable to resume query execution based on the saved query state data may be sent to customer computing devices for resuming query execution on-demand.

Abstract: A computing resource service provider may store user data in a distributed data storage system. The distributed data storage system may contain one or more storage partitions configured to store based at least in part on prefixes of keys contained in a key-value store, where the size of the keys may vary. The one or more storage partitions may track requests to access data where the requests include a key such that the data may be located by the service provider based at least in part on the key. When a request is received a skew value associated with the key included in the request may be determined. The skew value may be determined based at least in part on the ratio of rate estimators, where the rate estimators represent a weighted average of the movement of the keys in a key space. If the skew value exceeds a threshold the service provider may take mitigating action.

Abstract: A consistent view of associations between independently replicated data objects may be provided. Data objects may be stored in separate data stores. Copies of the data stores may also store the data objects. The copies of the data stores may independently receive the data objects to be stored as part of independently replicating data stores to one or more copies of the data stores. An association can be created between objects in the different data store. If when the association is created it is determined that a referenced object is not yet stored in a copy of a data store, then both the association and the referenced object may be stored in the same data store so that the association and the referenced object are replicated together to a copy of the same data store.

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: A method and system for generating permissions policies and permission boundary policies are described. The system receives a first request from a central administrator to create a delegated administrator, the first request specifying with one or more access permissions. The system generates a permission boundary policy that specifies the one or more access permissions and a first permissions policy that grants permissions to the delegated administrator to at least one of create an IAM principal with the permission boundary policy or attach a second permissions policy to the IAM principal. An effective permission given to the IAM principal is an intersection of access permissions specified in the first permissions policy and the one or more access permissions in the permission boundary policy. The system attaches the first permissions policy and the permission boundary policy to the delegated administrator.

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: 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.