Abstract: Valve seats include a flexible arm portion configured to seal against a portion of a valve body of a valve. A ball valve may include such valve seats. Methods of forming a seal in a ball valve include forcing a first metal valve scat into sealing contact with a first end cap and a ball valve member with a first metal flexible arm member and forcing a second metal valve seat into sealing contact with a second end cap and the ball valve member with a second metal flexible arm member.

Abstract: A key-value pair comprising a key and a value associated with the key is stored in a current segment of a data container. The key comprises a segment identifier identifying the current segment. The data container comprises a plurality of segments residing on a non-volatile memory device. Responsive to determining that a size of the current segment exceeds a threshold, a new segment is added to the container. The plurality of key-value pairs having respective current segment identifiers referencing one or more least recently created segments of the data container is deleted.

Abstract: A first data structure lock to access a first data structure of a first set of data structures to perform an operation associated with a transaction is acquired. The operation associated with the transaction is executed, wherein the operation is one of inserting the transaction into the first data structure or removing the transaction from the first data structure. An oldest active transaction of the first data structure is identified. A globally oldest active transaction of the set of the data structures in view of the oldest active transaction is determined. A second set of data structures is accessed, the second set of data structures including information associated with completed transactions to identify a set of data locks associated with completed transactions each having a transaction completion identifier that satisfies a condition when compared to a transaction start identifier associated with the globally oldest active transaction. The set of data locks are released.

Abstract: An example method of cursor seek operations using deleted record spans in memory sub-systems comprises: receiving, by a processing device, a request to search for a first data element of a key-value data store, the request specifying a first key associated with the first data element; determining that the first key is within a range of deleted data elements comprising a plurality of deleted data elements of the key-value data store; identifying a tail key associated with a tail element of the range of deleted data elements; identifying a second data element in the key-value data store, wherein the second data element is associated with a second key that follows the tail key in a specified order of keys; and providing the second data element in response to the request.

Abstract: Aspects of the present disclosure provide for operations of a key-value store (KVS) that uses journaling with storage of data (e.g., key data or value data of a key-value pair) in different types of data storage objects (e.g., data storage formats) selected based on one or more criteria.

Abstract: A KVS tree database and operations thereon are described herein. A KVS tree database is a multilevel tree that includes a base level and subsequent levels. The base level includes a heterogeneous kvset in a node, The heterogeneous kvset including entries for multiple KVS trees, such as a first entry for a first KVS tree and a second entry for a second KVS tree. The subsequent level includes a first node including a first homogeneous kvset for the first KVS tree and a second node including a second homogeneous kvset for the second KVS tree. Here, a homogeneous kvset includes nodes from only one KVS tree. The KVS tree database also includes a first determinative mapping of entries between the base level and the subsequent level and a second determinative mapping of entries between subsequent levels.

Abstract: Aspects of the present disclosure provide for operations of a key-value store (KVS) that uses journaling with storage of data (e.g., key data or value data of a key-value pair) in different types of data storage objects (e.g., data storage formats) selected based on one or more criteria.

Abstract: Systems and techniques for stream selection from multi-stream storage devices. Notification of a KVS tree write request for a multi-stream storage device is received. The notification includes a KVS tree scope corresponding to data in the write request. A stream identifier (ID) is assigned to the write request based on the KVS tree scope and a stability value of the write request. The stream ID is returned to govern stream assignment to the write request, the stream assignment modifying a write operation of the multi-stream storage device.

Abstract: Systems and techniques for collecting and using merge tree garbage metrics are described herein. A kvset is created for a node in a KVS tree. Here, a set of kvset metrics for the kvset are computed as part of the node creation. The kvset is added to the node. The node is selected for a compaction operation based on a metric in the set of kvset metrics. The compaction operation is performed on the node.

Abstract: Systems and techniques for merge tree modifications for maintenance operations are described herein. A request for a KVS tree is received. Here, the KVS tree is a data structure including nodes and the nodes include a temporally ordered sequence of kvsets that store keys in sorted order. A parameter set for the KVS tree is received. The request is executed on the KVS tree by modifying operation of the KVS tree in accordance with the parameter.

Abstract: A KVS tree database and operations thereon are described herein. A KVS tree database is a multilevel tree that includes a base level and subsequent levels. The base level includes a heterogeneous kvset in a node, The heterogeneous kvset including entries for multiple KVS trees, such as a first entry for a first KVS tree and a second entry for a second KVS tree, The subsequent level includes a first node including a first homogeneous kvset for the first KVS tree and a second node including a second homogeneous kvset for the second KVS tree. Here, a homogeneous kvset includes nodes from only one KVS tree. The KVS tree database also includes a first determinative mapping of entries between the base level and the subsequent level and a second determinative mapping of entries between subsequent levels.

Abstract: A KVS tree and operations thereon are described herein. A key-value set (kvset) is received to store in a key-value data structure on at least one machine readable medium. The kvset includes a mapping of unique keys to values with the keys and the values of the kvset being immutable. The key-value data structure is organized as a tree with nodes of the tree including a temporally ordered sequence of kvsets. The kvset, once received, is written to a sequence of kvsets of a root-node of the tree.

Abstract: A KVS tree and operations thereon are described herein. A key-value set (kvset) is received to store in a key-value data structure on at least one machine readable medium. The kvset includes a mapping of unique keys to values with the keys and the values of the kvset being immutable. The key-value data structure is organized as a tree with nodes of the tree including a temporally ordered sequence of kvsets. The kvset, once received, is written to a sequence of kvsets of a root-node of the tree.

Abstract: Systems and techniques for stream selection from multi-stream storage devices. Notification of a KVS tree write request for a multi-stream storage device is received. The notification includes a KVS tree scope corresponding to data in the write request. A stream identifier (ID) is assigned to the write request based on the KVS tree scope and a stability value of the write request. The stream ID is returned to govern stream assignment to the write request, the stream assignment modifying a write operation of the multi-stream storage device.

Abstract: Systems and techniques for merge tree modifications for maintenance operations are described herein. A request for a KVS tree is received. Here, the KVS tree is a data structure including nodes and the nodes include a temporally ordered sequence of kvsets that store keys in sorted order. A parameter set for the KVS tree is received. The request is executed on the KVS tree by modifying operation of the KVS tree in accordance with the parameter.

Abstract: Systems and techniques for collecting and using merge tree garbage metrics are described herein. A kvset is created for a node in a KVS tree. Here, a set of kvset metrics for the kvset are computed as part of the node creation. The kvset is added to the node. The node is selected for a compaction operation based on a metric in the set of kvset metrics. The compaction operation is performed on the node.

Abstract: Aspects of the present disclosure provide for operations of a key-value store (KVS) that uses journaling with storage of data (e.g., key data or value data of a key-value pair) in different types of data storage objects (e.g., data storage formats) selected based on one or more criteria.

Abstract: Systems and techniques for reducing probabilistic filter query latency are described herein. A query for a probabilistic filter that is stored on a first media may be received from a caller. In response to receiving the query, cached segments of the probabilistic filter stored on a second media may be obtained. Here, the probabilistic filter provides a set membership determination that is conclusive in a determination that an element is not in a set. The query may be executed on the cached segments resulting in a partial query result. Retrieval of remaining data of the probabilistic filter from the first media to the second media may be initiated without intervention from the caller. Here, the remaining data corresponds to the query and data that is not in the cached segment. The partial query results may then be returned to the caller.

Abstract: Systems and techniques for reducing probabilistic filter query latency are described herein. A query for a probabilistic filter that is stored on a first media may be received from a caller. In response to receiving the query, cached segments of the probabilistic filter stored on a second media may be obtained. Here, the probabilistic filter provides a set membership determination that is conclusive in a determination that an element is not in a set. The query may be executed on the cached segments resulting in a partial query result. Retrieval of remaining data of the probabilistic filter from the first media to the second media may be initiated without intervention from the caller. Here, the remaining data corresponds to the query and data that is not in the cached segment. The partial query results may then be returned to the caller.

Abstract: Systems and techniques for reducing probabilistic filter query latency are described herein. A query for a probabilistic filter that is stored on a first media may be received from a caller. In response to receiving the query, cached segments of the probabilistic filter stored on a second media may be obtained. Here, the probabilistic filter provides a set membership determination that is conclusive in a determination that an element is not in a set. The query may be executed on the cached segments resulting in a partial query result. Retrieval of remaining data of the probabilistic filter from the first media to the second media may be initiated without intervention from the caller. Here, the remaining data corresponds to the query and data that is not in the cached segment. The partial query results may then be returned to the caller.