Abstract: A database system is operable to determine a query for execution that requires access to a set of records stored by the database system. A first proper subset of the set of records are accessed in conjunction with executing the query by reading exactly one of a set of multiple replicas of each record of the first proper subset of the set of records from the replication-based storage system. A second proper subset of the set of records are accessed in conjunction with executing the query by reading at least one redundancy-coded segment from the redundancy-coding based storage system. A final resultant for the query is generated by performing at least one query operation on the first proper subset of the set of records and the second proper subset of the set of records in conjunction with executing the query.

Abstract: A node of a database system is operable to receive a plurality of data blocks from a set of source nodes via a set of relay nodes. At least one feedback data block to be sent to at least one of the set of source nodes is generated. Feedback relay node selection data selecting at least one of a plurality of nodes in the database system for facilitating routing of the at least one feedback data block from the node to the at least one of the set of source nodes via a prioritized feedback communication mechanism is generated. The at least one feedback data block is sent to the at least one of the plurality of nodes selected in the feedback relay node selection data. The at least one feedback data block is routed from the node to the at least one of the set of source nodes via the prioritized feedback communication mechanism.

Abstract: Apparatus to regulate fluid flow are disclosed. The apparatus includes an example regulator valve and an example automatically-adjusting or self-adjusting amplifier valve to maintain fluid flow during low downstream demand fluid flow conditions, and to maintain the operational accuracy and stability of the regulator valve during higher downstream demand fluid flow conditions.

Abstract: Apparatus to regulate fluid flow are disclosed. The apparatus includes an example regulator valve and an example automatically-adjusting or self-adjusting amplifier valve to maintain fluid flow during low downstream demand fluid flow conditions, and to maintain the operational accuracy and stability of the regulator valve during higher downstream demand fluid flow conditions.