A distributed database processing system for a database composed of data records organized into tables which processes unique index atoms consistently and concurrently. Each attempt to insert a new key value into such a unique index atom in any given node is routed to a unique index atom chairman for processing. The chairman determines whether the request will be granted. If the request is not granted, the requesting unique index atom continues to try to submit the insert. If the request is granted, the requesting unique index atom modifies the content thereof and broadcasts a replicated given unique index atom all other nodes that contain the replicated unique index atom.

A method, apparatus, and computer program product for communicating real-time updates among web clients. A structured data object is composed from a set of data nodes according to a domain specific language in response to requesting access to a data within a human resources database. The structured data object is interpreted within a context of a record ID/form to identify content for the web page and to determine whether real-time updates are enabled for the web page. Interpreting the structured data object, displays the form with the content. An event queue is created and a connection to the server hub is established when real-time updates are enabled. In response to receiving an update event in the event queue, a notification of the update event is displayed when the update event matches the record ID/form that a first user has opened.

An information processing device includes a memory, and a processor coupled to the memory and configured to acquire a plurality of data from first databases, where the data are stored in the first databases in a first period, and identifiers are stored in the first databases in association with the data, where the first databases correspond to servers that perform manipulations on a plurality of records containing the data stored in a second database, and the identifiers indicate order of the manipulations, and store the data in a third database in order indicated by the identifiers.

A method of maintaining a distributed ledger at a client node includes: storing a distributed ledger defining a plurality of records each containing a set of values; storing (i) a local voting weight corresponding to the client node, and (ii) respective remote voting weights for a plurality of remote client nodes; obtaining a proposed update to a record of the distributed ledger; generating a local vote to apply or discard the proposed update and transmitting the local vote to the remote client nodes; receiving remote votes to apply or discard the proposed update from the remote client nodes; determining whether to permit the proposed update based on (i) the local vote and the local voting weight, and (ii) the remote votes and the corresponding remote voting weights; and according to the determination, applying the proposed update to the distributed ledger or discarding the proposed update.

The invention relates to a computer-implemented method for exchanging information, through a DAG/Hashgraph consensus algorithm via a gossip protocol, the method includes making a first given node select a second given node randomly and send reference information; determining based on the reference information which node events are in front of that of the others; if the reference information implies that the events of the first given node is in front of that of the second given node, then sending a cancellation information to the first given node, preventing, in consequence, the first given node from sending DAG-event information to the second given node; if the reference information implies that the events of the second given node is in front of that of the first given node, then making the first given node send DAG-event information to the second given node; and soon through the network.

A data hub for servicing data hub dependent data consumers includes a persistent storage and a data validator. The persistent storage stores validated data. The data validator obtains a data validation request; in response to obtaining the data validation request: imports data from a data aggregator to obtain the validated data; performs a continuity analysis of the validated data to generate a data deviation report; and provides a portion of the validated data to one of the data hub dependent data consumers.

With the method for snapshotting metadata, in response to reaching a current snapshot moment, a second basic version number of a binary search tree in a database at the current snapshot moment is generated according to a first basic version number at a previous snapshot moment; during a process from the current snapshot moment to a next snapshot moment, whenever metadata in the database is updated, the binary search tree is updated according to the updated metadata, and an updated version number of the binary search tree after each update is generated according to the second basic version number; and in response to reaching the next snapshot moment, a snapshot operation is performed on binary search trees corresponding to all version numbers generated between the current snapshot moment and the next snapshot moment to generate snapshot information of the current snapshot moment.

A global secondary index method for a distributed database, includes: obtaining original data to be written in response to a database writing request; writing the original data into the distributed database; performing global secondary index processing on the original data written into the distributed database to obtain global secondary index data; establishing global secondary index tables between the global secondary index data and data table primary keys in the distributed database; and writing the global secondary index tables into an index shards based on an asynchronous processing manner.

According to aspects of the disclosure, there is provided a scalable cloud distributed database system for hosting data of multiple database tenants. In some embodiments, the database may be serverless. The serverless database may be configured to automatically and dynamically match resources to workload demands for tenants of the database. Databases described herein may include replica sets hosting multiple tenants. Tenants may be migrated from one replica set to another replica set based on usage. Usage of tenants may be throttled during migration between replica sets. Tenants with lower usage may be selected for migration between replica sets. During migration, files containing both a document and a history of updates to the document may be migrated. Databases described herein may include multiple storage tiers having different read and/or write speeds.

Methods and systems for executing non-blocking transactions at a database are provided. The method includes receiving a write transaction that is directed to a partition of a table stored by a cluster of database nodes. The method includes generating, at a database node of the cluster, a synthetic timestamp based on a first time associated with the database node and a duration, wherein the synthetic timestamp exceeds the first time by the duration. The method includes executing, based on determining the synthetic timestamp, one or more operations of the write transaction at one or more replicas of the partition. The method includes committing, based on a threshold number of acknowledgements, the one or more operations of the write transaction at the one or more replicas. The method includes sending, based on a second time exceeding the synthetic timestamp, an indication of success of the write transaction.