Abstract: A system includes a memory device, and a processing device, operatively coupled with the memory device, to perform operations including detecting a failure of a key-value store, identifying a non-filled zone of the memory device resulting from the failure, wherein the non-filled zone stores, in the key-value store, at least one of: an uncommitted key block or an uncommitted value block, and recovering the non-filled zone to obtain a recovered zone.

Abstract: A system and method for updating a configuration of a host system so that the memory sub-system of the host system emulates performance characteristics of a target memory sub-system. An example system includes a memory sub-system; and a processor, operatively coupled with the memory sub-system, to perform operations comprising receiving a request to emulate a characteristic of a target memory sub-system, identifying a candidate configuration that generates a load on a memory sub-system of a host system to decrease a characteristics of the memory sub-system of the host system, and updating a configuration of the host system based at least on the candidate configuration, wherein the updated configuration changes the memory sub-system of the host system to emulate the characteristic of the target memory sub-system.

Abstract: A memory system includes a memory device comprising a content addressable memory (CAM) block comprising a plurality of key tables each storing a respective plurality of stored search keys. The memory system further includes a processing device that receives, from a requestor, an input search key and an indication of one of the plurality of key tables and identifies a match between the input search key and one of the plurality of stored search keys in the one of the plurality of key tables. The one of the plurality of stored search keys has an associated offset value indicating a location in a sorted string table (SSTable) corresponding to the one of the plurality of key tables. The processing device further reads the offset value from the one of the plurality of key tables and returns, to the requestor, the offset value read from the one of the plurality of key tables. The requestor can retrieve, from the location in the SSTable, data representing a value associated with the input search key.

Abstract: A system includes a memory device, and a processing device, operatively coupled with the memory device, to perform operations including detecting a failure of a key-value store, identifying a non-filled zone of the memory device resulting from the failure, wherein the non-filled zone stores, in the key-value store, at least one of: an uncommitted key block or an uncommitted value block, and recovering the non-filled zone to obtain a recovered zone.

Abstract: A system and method for updating a configuration of a host system so that the memory sub-system of the host system emulates performance characteristics of a target memory sub-system. An example system includes a memory sub-system; and a processor, operatively coupled with the memory sub-system, to perform operations comprising receiving a request to emulate a characteristic of a target memory sub-system, identifying a candidate configuration that generates a load on a memory sub-system of a host system to decrease a characteristics of the memory sub-system of the host system, and updating a configuration of the host system based at least on the candidate configuration, wherein the updated configuration changes the memory sub-system of the host system to emulate the characteristic of the target memory sub-system.

Abstract: A system includes a zoned memory device allocating a zone storing a block belonging to a key-value set, and a processing device, operatively coupled with the zoned memory device, to perform operations including obtaining zone status information associated with the zone, identifying that the zone is a non-filled zone in view of the zone status information, and recovering the non-filled zone to obtain a recovered zone.

Abstract: A system and method for updating a configuration of a host system so that the memory sub-system of the host system emulates performance characteristics of a target memory sub-system. An example system determining a configuration of the host system, the host system comprising a memory sub-system; receiving, by a processing device, a request to emulate a characteristic of a target memory sub-system; analyzing a plurality of candidate configurations for the host system, wherein the plurality of candidate configurations comprises a candidate configuration that generates a load on the memory sub-system to decrease characteristics of the memory sub-system; and updating the configuration of the host system based on the plurality of candidate configurations, wherein the updated configuration changes the memory sub-system to emulate the characteristic of the target memory sub-system.

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: A system includes a zoned memory device allocating a zone storing a block belonging to a key-value set, and a processing device, operatively coupled with the zoned memory device, to perform operations including obtaining zone status information associated with the zone, identifying that the zone is a non-filled zone in view of the zone status information, and recovering the non-filled zone to obtain a recovered zone.

Abstract: A memory system includes a memory device comprising a content addressable memory (CAM) block comprising a plurality of key tables each storing a respective plurality of stored search keys. The memory system further includes a processing device that receives, from a requestor, an input search key and an indication of one of the plurality of key tables and identifies a match between the input search key and one of the plurality of stored search keys in the one of the plurality of key tables. The one of the plurality of stored search keys has an associated offset value indicating a location in a sorted string table (SSTable) corresponding to the one of the plurality of key tables. The processing device further reads the offset value from the one of the plurality of key tables and returns, to the requestor, the offset value read from the one of the plurality of key tables. The requestor can retrieve, from the location in the SSTable, data representing a value associated with the input search key.

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: 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: 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 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: 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.