The invention describes a method for determining a storage location of a database object of a specific version, wherein indexes for each version of the database object are stored in a trie having a root node corresponding to the specific version, the method comprising: determining a trie corresponding to the specific version by accessing the root node of the trie corresponding to the specific version; determining an object identifier of the database object by traversing the trie corresponding to the specific version using a secondary key related to the database object as search key; determining the storage location of the database object by traversing the trie corresponding to the specific version using the determined object identifier as search key.

A communications system implements instructions including maintaining a message object that includes an array of entries. Each entry of the array includes a field identifier, a data type, and a next entry pointer. The next entry pointers and a head pointer establish a linked list of entries. The instructions include, in response to a request to add a new entry to the message object, calculating an index based on a field identifier of the new entry and determining whether the entry at the calculated index within the array of entries is active. The instructions include, if the entry is inactive, writing a data type, field identifier, and data value of the new entry to the calculated index, and inserting the new entry into the linked list. The instructions include, if the entry is already active, selectively expanding the size of the array and repeating the calculating and determining.

A system and method is disclosed for managing data in a non-volatile memory. The system may include a non-volatile memory having multiple non-volatile memory sub-drives. A controller of the memory system is configured to route incoming host data to a desired sub-drive, keep data within the same sub-drive as its source during a garbage collection operation, and re-map data between sub-drives, separate from any garbage collection operation, when a sub-drive overflows its designated amount logical address space. The method may include initial data sorting of host writes into sub-drives based on any number of hot/cold sorting functions. In one implementation, the initial host write data sorting may be based on a host list of recently written blocks for each sub-drive and a second write to a logical address encompassed by the list may trigger routing the host write to a hotter sub-drive than the current sub-drive.

A method includes determining a health characteristic value of a block of memory cells, determining a difference between the health characteristic value and a health threshold, determining, based on the difference, a weight to associate with a block of memory cells, selecting, based on the weight, a block of memory cells for a media management operation; and performing a media management operation on the selected block of memory cells.

Embodiments of a system and method to prevent mass deletion of data in a data storage system. A data deletion operation comprises a delete operation marking blocks to be deleted followed by a garbage collection (GC) operation to remove marked blocks from storage media. Based on historical information regarding deletions per GC cycle, the storage system can detect any significant deviations as potentially dangerous. If a deletion in excess of a deviation threshold is seen, the next GC operation is skipped to provide a delay period during which time the user can investigate the data delete command and restore data if necessary. De-risking conditions such as known abnormal high deletion periods or new system installation can be used to override any garbage collection delay.

An indication is received from a storage device that an attempt to read a portion of data from a block of the storage device has failed. A command is transmitted to the storage device to perform a scan on data stored at the block comprising the portion of data to acquire failure information associated with a plurality of subsets of the data stored at the block. The failure information associated with the plurality of subsets of the data stored at the block is received from the storage device.

Systems and methods for adapting garbage collection (GC) operations in a memory device to a pattern of host accessing the device are discussed. The host access pattern can be represented by how frequent the device is in idle states free of active host access. An exemplary memory device includes a memory controller to track a count of idle periods during a specified time window, and to adjust an amount of memory space to be freed by a GC operation in accordance with the count of idle periods. The memory controller can also dynamically reallocate a portion of the memory cells between a single level cell (SLC) cache and a multi-level cell (MLC) storage according to the count of idle periods during the specified time window.

Garbage collection processing in a distributed shared log system includes a client identifying obsoleted log entries for a shared data object. The client sends information associated with the identified obsoleted log entries to a shared log server. The shared log server receives information associated with obsoleted log entries from all clients in the distributed shared log system and uses the information to delete the obsoleted log entries. The shared log server can update a snapshot mark to indicate the earliest time that a snapshot of the shared log can be taken. The snapshot mark can be updated based on the information associated with obsoleted log entries.

A garbage collection technology for a storage medium that includes a plurality of blocks, where each storage unit has a collection parameter related to data in one of the blocks, and where each block includes a plurality of pages. A group of blocks is selected from the plurality of blocks based on the collection parameter. A difference between values of collection parameters of any two blocks in the group of blocks is not greater than a preset value. Data in a first valid page and a second valid page in the group of blocks is replicated to a same destination block, to facilitate garbage collection.

A garbage data scrubbing method includes obtaining an input/output (IO) busy/idle status of a terminal at a current moment, where the IO busy/idle status includes a busy state and an idle state. When the IO busy/idle status of the terminal at the current moment is the idle state, a discard message is delivered to a storage device, where the discard message includes an initial address and a size of to-be-scrubbed physical space in the storage device, and where the discard message is used to unbind a mapping relationship between a physical address of the to-be-scrubbed physical space and a corresponding logical address.