The present disclosure relates to a method in a distributed and non-hierarchical node comprising a set of data items for determining a synchronization state between said node and one or more distributed and non-hierarchical nodes communicatively coupled to form a cluster, wherein the set of data items are locally replicated at each node. The method comprises generating a snapshot comprising information relating to the set of data items at a snapshot time T.sub.s, said information identifying changes to the data items where each change comprises a time stamp, where only changes to the data items with a time stamp<T.sub.0, where T.sub.s>T.sub.0, are included in the snapshot, although changes to the data items up to the time T.sub.s, have been received and stored in the nodes, receiving corresponding generated snapshots from all other nodes in the cluster, and determining a synchronization state based on a comparison between the generated and received snapshots. The synchronization state is determined to be not synchronized if the generated snapshot and the received corresponding snapshots do not all match.

In some embodiments, a system for synchronizing content with client devices receives a request from a client device to synchronize operations pertaining to content items associated with a user account registered at the system. The request can include the operations and a cursor identifying a current position of the client in a journal of revisions on the system. Based on the operations, the system generates linearized operations associated with the content items. The linearized operations can include a respective operation derived for each of the content items from one or more of the operations. The system converts each respective operation in the linearized operations to a respective revision for the journal of revisions and, based on the cursor, determines whether the respective revision conflicts with revisions in the journal. When the respective revision does not conflict with revisions in the journal, the system adds the respective revision to the journal.

Technologies are described providing adaptive query routing in a replicated database environment. The technologies can be used with a variety of replication protocols. Prepared statements, such as for queries, from a database client can be routed to a source node, or a source node and available replica nodes, when a replica node becomes unavailable. When a replica node becomes available again, a prepared statement can be updated to indicate that the updated prepared statement can be executed at nodes including the replica node that is available again. Prepared statement routing can also be used when a portion of replicated data becomes unavailable at a replica node, but a portion of replicated data remains available.

In response to an allocation request of a target transaction, transaction allocation indexes respectively corresponding to the at least two node devices are determined. A coordinator node device of the target transaction in the at least two node devices is determined based on the transaction allocation indexes respectively corresponding to the at least two node devices. The coordinator node device coordinates the target transaction. Each coordinator node device coordinates a transaction as a decentralized device so that the transaction can be processed across nodes, which is conducive to improving efficiency of transaction processing, reliability of transaction processing, and system performance of a database system.

An image processing device includes a vision sensor and a processor. The vision sensor generates a plurality of events in which an intensity of light changes and generates a plurality of timestamps depending on times when the events occur. In addition, the processor may regenerate a timestamp of a pixel where an abnormal event occurs, based on temporal correlation of the events.

This application discloses a transaction processing method and apparatus, a computer device, and a storage medium, and relates to the technical field of databases. The method includes: obtaining a read set and a write set of a target transaction in response to a read-write operation of the target transaction; determining a logical begin time and a logical end time of the target transaction in response to a validation instruction of the target transaction; updating the logical begin time based on the write set in response to the logical begin time and the logical end time conforming to a concurrent consistency level of the target transaction, to obtain an updated logical begin time; and committing the target transaction in response to the updated logical begin time being less than or equal to the logical end time.

A self-healing data synchronization process includes an initial stage in which a collection of data change events is received, a set of data record(s) corresponding to the data change event(s) is identified, and a syncing of the set of data record(s) is initiated. Data that indicates which data record(s) successfully synced and which failed is stored. During a subsequent stage of the self-healing process, data change events that occurred during a preceding time horizon are identified, a corresponding first set of data record(s) are identified, a difference between the first set and a second set of data record(s) that successfully synced during the time horizon is determined as a third set of data record(s), and any data record that was attempted to be synced during the time horizon but failed is excluded from the third set. A sync of any data record remaining in the third set is then initiated.

A device may receive a first telemetry data entry associated with an attribute and store a record associated with the first telemetry data entry, wherein the record identifies a first context value associated with the attribute. The device may log a first timestamp of the first telemetry data entry in a lookup table, wherein the lookup table includes a mapping of the attribute to the first context value and to the first timestamp. The device may receive a second telemetry data entry associated with the attribute and may determine, from the mapping, that the second telemetry data entry is associated with a second context value that is different from the first context value. The device may determine whether a second timestamp, of the second telemetry data entry, is before the first timestamp. The device may perform an action based on whether the second timestamp is before the first timestamp.

Systems, methods, and devices for generating a transactional change tracking summary for a database. A method includes executing a transaction on a table of a database, wherein the table includes a micro-partition and the transaction is executed on the micro-partition. The method includes, in response to the transaction being fully executed, generating a change tracking entry comprising an indication of one or modifications made to the table by the transaction. The method includes storing the change tracking entry in a change tracking stream, wherein the change tracking stream includes one or more sequential change tracking entries that each correspond to a different transaction that is fully executed on the table.

Techniques described herein relate to a method for distributed data management. The method may include making a first determination that data is written to a data structure of storage of a data host; obtaining, based on the first determination, data information associated with the data; making a second determination of intent corresponding to the data; generating a global name and metadata corresponding to the data, wherein the metadata comprises the intent; and publishing the global name and the metadata to a global name repository.