Abstract: A database controller for a database of data items distributed across a plurality of storage units. The database controller configured to store an ordered list comprising, for each of the data items individually, the identifying information of the storage unit upon which the data item is stored. The database controller configured to maintain a frequency record, recording the values of prefix portions of the data items and the number of data items having each prefix portion. Wherein, the ordered list and the frequency record are ordered by applying the same ordering metric to the prefix portions. The database controller being configured to receive a range query specifying a search prefix portion, to use the frequency record to calculate where to find in the ordered list the identifying information of storage units storing the data items having the search prefix, and using that identifying information to retrieve query results.

Abstract: A querying method for a database of graph data encoded as triples being stored on storage servers. The method including dividing a query into a plurality of result criteria triple patterns which query results match, each triple pattern element being either: a single value triple pattern element; or a variable value triple pattern element specifying an ID of a variable. The method includes forming one or more sub-queries each having triple patterns having the same single value triple pattern element or specifying the same ID of a variable as a variable value triple pattern element, issuing each formed sub-query to each of the servers, and receiving triples satisfying a sub-query as results from the servers and using the sub-query results in as a response to the query.

Abstract: A database of graph data encoded as triples, each including a subject, a predicate, and an object, and each stored within a data item of data items ordered according to their data and distributed across a plurality of nodes of a distributed network; where the node to which each of the data items is mapped is dependent upon the position of the item within the set; and each triple is stored in two or more items each having a different configuration from among the following: —a first in which the subject precedes the predicate and the object in the item; —a second in which the predicate precedes the subject and the object in the item; and —a third in which the object precedes the subject and the predicate in the item.

Abstract: A database controller controls a database for storing graph data encoded as triples, each triple having a subject, a predicate, and an object, and each stored within a data item among a set of data items ordered according to the triple stored within. Each data item is stored on a storage node from among a plurality of storage nodes distributed in a network. The database controller includes a storage request receiver configured to receive a request to store a triple in the database, and a data item generation module configured to generate two or more data items each having a different version of the triple.

Abstract: A distributed data graph storage system, to store a data graph representing information as vertices interconnected by edges denoting relationships between connected vertices, the data graph being a plurality of graph partitions. The data graph storage system includes data storage servers to store data portions, each portion encodes a graph partition; a data portion distribution controller, when the data portions each encode a same graph partition, to allocate the portions to different data storage servers; a data access module to receive access requests for the data graph and to distribute the access requests among the servers; a graph partition usage monitor to record statistics representing the distribution of data access events caused by the access requests; where the data portion distribution controller is configured to increase or decrease the number of portions in dependence upon the recorded statistics.

Abstract: Embodiments of the present invention include a database controller for a database of information encoded as a set of data items distributed among a plurality of storage units distinguishable from one another by respective identifying information and each data item comprising a value of each of two or more data elements, the set of data items having a prescribed order of the two or more data elements of which the first one or two data elements are assigned as a prefix portion.

Abstract: Embodiments include a database controller for a database of information encoded as a set of data items, the database controller comprising: a segment control module configured to divide the set of data items into a series of segments, each segment comprising each of the data items falling within defined lower limit and upper limit values of an ordering metric used to place the data items in order; and an adaptive segment locator module configured to manage the distribution of the series of segments among a plurality of storage units, including selecting which segments from among the series of segments to co-locate on the same storage unit based on historical data representing read operations performed on the database.

Abstract: A querying method for a database of graph data encoded as triples being stored on storage servers. The method including dividing a query into a plurality of result criteria triple patterns which query results match, each triple pattern element being either: a single value triple pattern element; or a variable value triple pattern element specifying an ID of a variable. The method includes forming one or more sub-queries each having triple patterns having the same single value triple pattern element or specifying the same ID of a variable as a variable value triple pattern element, issuing each formed sub-query to each of the servers, and receiving triples satisfying a sub-query as results from the servers and using the sub-query results in as a response to the query.

Abstract: Embodiments include a data storage system comprising: a relational database storage apparatus configured to store a relational database comprising rows of relational data having an entry in each of a plurality of headed columns; a graph database storage apparatus configured to store a graph database including graph data related to the relational data, the graph database being encoded as triples; a query handler configured to receive a relational data query specifying a condition which defines a subset of one or more rows of relational data from which an entry is included in the query results; wherein the query handler is configured to generate a graph data query to search the graph database for graph data related to the subset of one or more rows of relational data.

Abstract: A database controller controls a database for storing graph data encoded as triples, each triple having a subject, a predicate, and an object, and each stored within a data item among a set of data items ordered according to the triple stored within. Each data item is stored on a storage node from among a plurality of storage nodes distributed in a network. The database controller includes a storage request receiver configured to receive a request to store a triple in the database, and a data item generation module configured to generate two or more data items each having a different version of the triple.

Abstract: Embodiments of the present invention provide a database of graph data encoded as triples, each comprising a subject, a predicate, and an object, and each stored within a data item among a set of data items ordered according to their data and distributed across a plurality of nodes of a distributed network of nodes; wherein the node to which each of the data items is mapped is dependent upon the position of the data item within the ordered set; and each triple is stored in two or more data items each having a different configuration from among the following: a first configuration in which the subject precedes the predicate and the object in the data item; a second configuration in which the predicate precedes the subject and the object in the data item; and a third configuration in which the object precedes the subject and the predicate in the data item.