Neo4j Sweden Ab

Neo Technology, Inc.

James Webber

Mats Tobias Lindaaker

Alistair Philip Campbell Jones

Niels De Jong

Ian S Robinson

Irfan Nuri Karaca

Hugo Firth

A database system with a transactional commit protocol based on a safe conjunction of majorities is disclosed. In various embodiments, a directed acyclic graph comprises, for each of a plurality of transactions, data identifying the transaction, data indicating prior transaction(s) on which the transaction depends, and data indicating whether the transaction has been committed. A processor associated with a resource manager of a first database server included in a plurality of database servers each having a resource manager, determines a leading edge comprising a set of committed leaf nodes of the directed acyclic graph. The processor provides data representing a respective leading edge from each respective resource manager, and determines to commit a transaction based on a determination that a majority of the resource managers have indicated they agree on a consistent starting state and ending state for the transaction.

Database system with transactional commit protocol based on safe conjunction of majorities

Techniques are disclosed to provide guided natural language interactions with a connected data system, such as a graph database. In various embodiments, natural language input associated with a graph database query associated with a graph data set is received. The natural language input is processed to generate a set of candidate strings. At least a subset of the candidate strings is mapped to an entity in the graph data set. The entity and data comprising the graph data are used set to determine a candidate graph pattern associated with the graph database query. The candidate graph pattern is used to guide a user associated with the natural language input to refine the graph database query.

Pre-emptive graph search for guided natural language interactions with connected data systems

A method and apparatus for estimating the cardinality of graph pattern queries using graph statistics and metadata is presented. In various embodiments, node and edge labels are used to compute estimates for graph patterns (bi-grams) and the estimates for these patterns as composed to provide cardinality estimates of longer paths. The computation of bi-grams is low cost and requires only minimal changes to the existing query planner in the existing database machinery to be useful. The resulting estimates are used during query execution to minimize the amount of work needed to complete a query and return a faithful and accurate answer to the user. The apparatus includes modules containing computer-executable instructions to perform the above method.

Bi-gram cardinality estimation in a graph database

A database system with a transactional commit protocol based on a safe conjunction of majorities is disclosed. In various embodiments, a directed acyclic graph comprising, for each of a plurality of database transactions, data identifying the transaction, data indicating one or more prior database transactions on which the database transaction depends, and data indicating whether the transaction has been committed is stored. A leading edge comprising a set of committed leaf nodes of the directed acyclic graph is determined. Data representing the leading edge is provided to a transaction coordinator configured to use the leading edge to determine based at least in part on the leading edge to commit a transaction.

Techniques are disclosed to safely and performantly store data in a distributed graph database. In various embodiments, a combination of a replication protocol for data redundancy with a chain-commit protocol is used to ensure a safe ordering of concurrent updates across servers. The resulting protocol allows a distributed graph database to simultaneously uphold ACID properties and a useful degree of scalability through concurrent processing of updates in the typical case, and serialization of updates only where data integrity would otherwise be at risk.

Graph database system to safely store data at high volume and scale

Methods of conducting database transactions. One such method comprises receiving data to be written to a database; identifying a set of shard replicas corresponding to the database to which the data is to be written; transmitting, to each of the replicas in the set, a request to write the data thereto; receiving votes back from the replicas in the set, each vote representing whether the respective replica commits to a writing of the data thereto; determining whether to commit to the writing of the data to the database according to whether a majority of the replicas of every shard having replicas in the set has transmitted a vote committing to the writing of the data thereto; and transmitting an outcome of the determining to each of the replicas in the set.

Method and apparatus for ensuring consistent outcomes in updates to distributed databases

A method and apparatus for partitioning a graph database that includes nodes connected to one another is presented. The method entails determining a node type indicating a type of node that is to be used as mapped nodes, and upon receiving a new node, placing the new node in a partition according to one or more property values associated with the new node if it is a mapped node, and placing the new node in a partition according to its connections to other nodes if it is not a mapped node. The apparatus includes modules containing computer-executable instructions to perform the above method.

Growing community of inventors

London, United Kingdom

James Webber