Abstract: A method for performing a backup in relation to a separated database, the method includes creating, by a processing circuit, a new backup log structured merge (LSM) tree of the separated database, wherein the new backup LSM tree is associated with a new point in time (PIT) and belongs to a group of LSM trees that comprise a primary LSM tree and one or more backup LSM trees that are associated with different PITs, and share a key value (KV) database that is mutable and is separated from the group; wherein the creating comprises storing the new backup LSM tree to a destination.

Abstract: The present teaching relates to a method, system and programming for recovering a data storage. In response to a failure of the data storage, a last checkpointed version is retrieved from a checkpoint file created previously for the failure of the data storage. A recovery table is updated to indicate the last checkpointed version and an incarnation number indicating a number of previous recovery of the data storage. The data storage is recovered based on the recovery table. A version number of the last checkpointed version is reset to zero upon a successful recovery of the data storage. The incarnation number is incremented.

Abstract: The present teaching relates to a method, system and programming for operating a data storage. The data storage comprises of different portions including: a first portion having a plurality of metadata objects stored therein, each of the metadata objects being associated with a filter and corresponding to a range of keys, wherein at least one of the metadata objects is associated with a data structure, and a second portion having a plurality of files stored therein, each of the plurality of files being associated with one of the plurality of metadata objects; The data storage synchronizes a scan request with respect to one or more write requests based on a parameter associated with the scan request and each of the one or more write requests.

Abstract: The disclosed embodiments describe techniques for isolating and managing models via versioning. In one embodiment, a method is disclosed comprising reading a configuration document associated with a first model; incrementing an internal write version of the configuration document; storing the internal write version in the configuration document; generating documents belonging to a second model such that respective document identifiers of the documents include a next external version a first field and the incremented internal write version in a second field; and uploading the documents to a serving system, causing the serving system to replace the first model with the second model.

Abstract: The present teaching relates to a system and method for providing a response to a query related to a data sketch. A local data sketch is obtained in response to a synchronization parameter being set to a first value. The data sketch is updated based on the obtained local data sketch. The synchronization parameter is set to a second value that is different than the first value and thereafter propagated. A response to a query is generated based on the updated data sketch.

Abstract: The present teaching relates to a method and system generating a data sketch. A plurality of local data sketches are generated, wherein for each local data sketch, it is determined whether a propagation condition is satisfied. In response to the condition being satisfied, the local data sketch is processed when a synchronization parameter satisfies a criterion. The synchronization parameter is set to a predetermined value to enable propagation of the local data sketch to the data sketch. Upon the local data sketch being propagated to the data sketch, the above steps are repeated.

Abstract: The present teaching relates to a method, system and programming for recovering a data storage. In response to a failure of the data storage, a last checkpointed version is retrieved from a checkpoint file created previously for the failure of the data storage. A recovery table is updated to indicate the last checkpointed version and an incarnation number indicating a number of previous recovery of the data storage. The data storage is recovered based on the recovery table. A version number of the last checkpointed version is reset to zero upon a successful recovery of the data storage. The incarnation number is incremented.

Abstract: The present teaching relates to a method, system and programming for searching a data storage. A key is extracted from a request and a metadata object associated with the key is identified. Further, a determination is made as to whether the metadata object is associated with a data structure stored in a first portion of the data storage. In response to a successful determination, the data structure is searched to retrieve a value associated with the key from the first portion. In response to an unsuccessful determination, a cache is searched to retrieve the value associated with the key, and in response to the key being absent in the cache, a file associated with the metadata object is searched to retrieve the value associated with the key, wherein the file is stored in a second portion of the data storage.

Abstract: The present teaching relates to a method, system and programming for operating a data storage. The data storage comprises of different portions including: a first portion having a plurality of metadata objects stored therein, each of the metadata objects being associated with a filter and corresponding to a range of keys, wherein at least one of the metadata objects is associated with a data structure, and a second portion having a plurality of files stored therein, each of the plurality of files being associated with one of the plurality of metadata objects; The data storage synchronizes a scan request with respect to one or more write requests based on a parameter associated with the scan request and each of the one or more write requests.

Abstract: The present teaching relates to concurrent database operation. In one example, a plurality of requests which includes a scan request to obtain first data associated with a plurality of first keys stored in a database is received concurrently. A global version number is updated upon receipt of the scan request. The first data associated with the plurality of first keys is obtained based on the updated global version number. The first data is provided in response to the scan request.

Abstract: The present teaching relates to a method, system and programming for operating a data storage. The data storage comprises of different portions including: a first portion having a plurality of metadata objects stored therein, each of the metadata objects being associated with a filter and corresponding to a range of keys, wherein at least one of the metadata objects is associated with a data structure, and a second portion having a plurality of files stored therein, each of the plurality of files being associated with one of the plurality of metadata objects; The data storage synchronizes a scan request with respect to one or more write requests based on a parameter associated with the scan request and each of the one or more write requests.

Abstract: In one embodiment, a set of lock and unlock instructions in a read phase of a computer-readable program is replaced with a first set of tracking instructions, wherein the first set of tracking instructions track a set of locked objects identifying objects that would have been locked by executing the set of lock and unlock instructions. A second set of tracking instructions is inserted into the read phase of the computer-readable program, wherein the second set of tracking instructions track a set of read objects indicating versions of objects that are read. Validation instructions are inserted into the computer-readable program, wherein the validation instructions validate that the versions of objects in the set of read objects have not changed since they were last read and lock the set of locked objects that would have been locked upon completing execution of the set of lock and unlock instructions.

Abstract: Briefly, embodiments disclosed herein relate to managing transactions in a distributed content transaction system.

Abstract: Disclosed herein is an enhanced device personalization that personalizes a user's experience with a device, e.g., a multi-user device. Rather than personalizing based on the specific user(s) that are using, an active entity, which represents a type of consumption, may be generated and used to make recommendations for personalizing an experience using the device. In a case of a multi-user device, each user's experience is personalized by determining an active entity for the user's experience and without knowledge of which user is using the device.

Abstract: Methods, systems, and programming for accessing data are described herein. In a non-limiting embodiment, a request associated with a key may be received. A memory chunk in a first memory site associated with the key may be located. An entry in the memory chunk corresponding to the key may be determined. A first pointer to the key corresponding to a first location of the key within a buffer at a second memory site may be obtained from the entry. The key stored at the first location may be retrieved from the buffer at the second memory site.

Abstract: The present teaching relates to a method, system and programming for searching a data storage. A key is extracted from a request and a metadata object associated with the key is identified. Further, a determination is made as to whether the metadata object is associated with a data structure stored in a first portion of the data storage. In response to a successful determination, the data structure is searched to retrieve a value associated with the key from the first portion. In response to an unsuccessful determination, a cache is searched to retrieve the value associated with the key, and in response to the key being absent in the cache, a file associated with the metadata object is searched to retrieve the value associated with the key, wherein the file is stored in a second portion of the data storage.

Abstract: The present teaching relates to a method, system and programming for operating a data storage. The data storage comprises of different portions including: a first portion having a plurality of metadata objects stored therein, each of the metadata objects being associated with a filter and corresponding to a range of keys, wherein at least one of the metadata objects is associated with a data structure, and a second portion having a plurality of files stored therein, each of the plurality of files being associated with one of the plurality of metadata objects; The data storage synchronizes a scan request with respect to one or more write requests based on a parameter associated with the scan request and each of the one or more write requests.

Abstract: The present teaching relates to a system and method for providing a response to a query related to a data sketch. A local data sketch is obtained in response to a synchronization parameter being set to a first value. The data sketch is updated based on the obtained local data sketch. The synchronization parameter is set to a second value that is different than the first value and thereafter propagated. A response to a query is generated based on the updated data sketch.

Abstract: The present teaching relates to a method and system generating a data sketch. A plurality of local data sketches are generated, wherein for each local data sketch, it is determined whether a propagation condition is satisfied. In response to the condition being satisfied, the local data sketch is processed when a synchronization parameter satisfies a criterion. The synchronization parameter is set to a predetermined value to enable propagation of the local data sketch to the data sketch. Upon the local data sketch being propagated to the data sketch, the above steps are repeated.

Abstract: Methods, systems, and programming for accessing data are described herein. In a non-limiting embodiment, a request associated with a key may be received. A memory chunk in a first memory site associated with the key may be located. An entry in the memory chunk corresponding to the key may be determined. A first pointer to the key corresponding to a first location of the key within a buffer at a second memory site may be obtained from the entry. The key stored at the first location may be retrieved from the buffer at the second memory site.