Abstract: According to one embodiment, a data virtualization apparatus includes a memory and a processor. The processor is configured to acquire first schema information including a first table name of a first source table managed in a first data source, and second schema information including a second table name of a second source table managed in a second data source, convert the first table name into a third table name, and convert the second table name into a third table name, and register first table correspondence information including the first table name and the third table name in the memory, and register second table correspondence information including the second table name and the third table name in the memory.

Abstract: A database server includes a database manager and a synchronization processing unit. When the database server is in a first state in which the database server receives requests from a client, the database manager updates a database in accordance with a request from the client and registers both update data for causing another database server included in the plurality of database servers to update a database of the other database server and management information of the update data for each data management unit in a memory on the basis of the request. When the database server is in the first state, the synchronization processing unit transmits the update data registered in the memory to the other database.

Abstract: A database management system according to an embodiment includes a first node and a plurality of second nodes. The first node receives a query for requesting data from a client terminal and transmits the received query to any one of a plurality of second nodes in accordance with conditions. The plurality of second nodes acquire data by performing processing based on the query received from the first node and transmit the acquired data to the first node. The first node holds range information indicating a range of data held in each of the second nodes and does not transmit the query to the second nodes when the range of data to be retrieved for the query is not a range indicated by the range information.

Abstract: Any one of a first storage area and a second storage area, in which redundant data are respectively written, is set as a reference storage area, reference data are read in accordance with a request from the storage area set as the reference storage area between the first storage area and the second storage area, and, when update data are received from an external storage device, information based on the update data is written in the storage area not set as the reference storage area between the first storage area and the second storage area and the information based on the update data is written in the storage area set as the reference storage area.

Abstract: A database server includes a database manager and a synchronization processing unit. When the database server is in a first state in which the database server receives requests from a client, the database manager updates a database in accordance with a request from the client and registers both update data for causing another database server included in the plurality of database servers to update a database of the other database server and management information of the update data for each data management unit in a memory on the basis of the request. When the database server is in the first state, the synchronization processing unit transmits the update data registered in the memory to the other database.

Abstract: A storage system includes a plurality of nodes, each of the nodes including a nonvolatile storage device, and a connection unit directly connected to at least one of the nodes. The connection unit is configured to determine a target node responsive to a write request generated by a host, determine whether or not the target node is busy, output a write command directed to a non-busy node such that data requested by the write request are written in the non-busy node, responsive to determining that the target node is busy, and output a copy command directed to the non-busy node such that the data written in the non-busy node are copied to the target node, after a reference time period has passed since determining that the target node is busy.

Abstract: A database management system according to an embodiment includes a first node and a plurality of second nodes. The first node receives a query for requesting data from a client terminal and transmits the received query to any one of a plurality of second nodes in accordance with conditions. The plurality of second nodes acquire data by performing processing based on the query received from the first node and transmit the acquired data to the first node. The first node holds range information indicating a range of data held in each of the second nodes and does not transmit the query to the second nodes when the range of data to be retrieved for the query is not a range indicated by the range information.

Abstract: According to one embodiment, a database management apparatus capable of operating as one of a plurality of servers constituting a distributed database in a tree structure includes a processor configured to manage server information of an own server and a subordinate server, analyze an input query, and decide a table used for the query, determine a generation number of query executing modules configured to execute the query, based on the server information of the own server and the subordinate server, and divide the query according to the generation number if a plurality of query executing modules is generated for a subordinate server and accumulate a result of the query executed by the query executing modules of the determined generation number.

Abstract: A storage system includes a plurality of nodes, each of the nodes including a processor and a nonvolatile storage device, and a connection unit directly connected to at least one of the nodes and configured to issue commands directed to a target node. The processor of the target node is configured to access the nonvolatile storage device of the target node in accordance with a command received from the connection unit, notify completion of processing for the command to the connection unit when a processing result responsive to the command is returned from the nonvolatile storage device of the target node within a reference time period, and notify a busy state of the target node to the connection unit when the processing result responsive to the command is not returned from the nonvolatile storage device of the target node within the reference time period.

Abstract: A storage system includes a storage unit having a plurality of routing circuits electrically networked with each other, each of the routing circuits being locally connected to a plurality of node modules, each of which includes nonvolatile memory, the plurality of node modules forming at least first and second storage regions, and a plurality of connection units, each connected to one or more of the routing circuits, and access the first and second storage regions through one or more of the routing circuits in accordance with a command. When one of the connection units receives a command to write second data into the first storage region while first data are being read out from the first storage region, said one of the connection units writes the second data into both the first and second storage regions.

Abstract: A storage system includes a plurality of storage devices, and a server including a memory and an interface. The server is configured to store, in the memory, each of data pieces that are received through the interface from a client as a series of data to be written, in association with a single write command or a series of write commands received through the interface from the client, for each data piece, determine a target storage device and a logical address thereof at which the data piece is to be written, based on an identifier of the data piece received in association with the data piece through the interface from the client, and carry out, in parallel, writing of the data pieces stored in the memory at the determined logical addresses.

Abstract: A search apparatus of an embodiment includes a query reception device, a data acquisition device, a decision device, and a determination device. The query reception device receives a query for searching for top N (N is a natural number) cases of data among cases of data that are targets. The data acquisition device acquires n cases of data (n is a natural number equal to or smaller than N) from each of a plurality of nodes distributively holding the cases of data that are targets on the basis of the query received by the query reception device. The decision device decides whether or not the top N cases of data can be settled from the n cases of data acquired by the data acquisition device. The determination device determines a node from which data will be acquired next time from among the plurality of nodes and the number of cases of data to be acquired when the decision device decides that the top N cases of data cannot be settled.

Abstract: The second communication device is in one level higher in a logical network forming a tree structure and sends data to the first communication device. The third communication device is in two or more levels higher in the logical network. The third device is configured to send data to the first communication device without passing through the second communication device. The first communication devices comprises a monitoring unit and a connection switching unit. The monitoring unit is configured to monitor an operation state of the second communication device. The connection switching unit is configured to send a request for sending data to the third communication device, in a case that the normal operation state of the second communication device is not confirmed by the monitoring unit.

Abstract: A database system is formed by connecting node devices in parent-child relations. Each of the node devices includes a data storing unit, a saving rule storing unit, a storage processing unit, and an inquiry processing unit. The saving rule storing unit stores a saving rule used for saving data stored in the data storing unit to a parent node device in a case in which its own node device is not a parent of a highest rank and deleting the data in a case in which its own node device is the parent of the highest rank. The storage processing unit writes data and saves data to be saved from the data storing unit into a parent node in an order represented by order information associated with the data or deletes data to be deleted by referring to the saving rule.

Abstract: A data retrieval system includes a first apparatus and a second apparatus. The first apparatus includes a distributor, a processing state receptor, and a completion determiner. The distributor distributes a query to one or more devices which can retain data. The processing state receptor receives, from the second apparatus, information indicating processing states of the devices for the query. The completion determiner determines whether the query is complete from the received processing state. The second apparatus includes a transceiver, a process manager, and a processing state transmission controller. The transceiver receives a query distributed by the first apparatus and transmits the query to the devices. The process manager manages a processing state indicating whether each device completes the query on the basis of a received processing result of the query of each device. The processing state transmission controller transmits managed processing states of the query to the first apparatus.

Abstract: A storage system includes a plurality of nodes, each of the nodes including a nonvolatile storage device, and a connection unit directly connected to at least one of the nodes. The connection unit is configured to determine a target node responsive to a write request generated by a host, determine whether or not the target node is busy, output a write command directed to a non-busy node such that data requested by the write request are written in the non-busy node, responsive to determining that the target node is busy, and output a copy command directed to the non-busy node such that the data written in the non-busy node are copied to the target node, after a reference time period has passed since determining that the target node is busy.

Abstract: A storage system includes a plurality of nodes, each of the nodes including a processor and a nonvolatile storage device, and a connection unit directly connected to at least one of the nodes and configured to issue commands directed to a target node. The processor of the target node is configured to access the nonvolatile storage device of the target node in accordance with a command received from the connection unit, notify completion of processing for the command to the connection unit when a processing result responsive to the command is returned from the nonvolatile storage device of the target node within a reference time period, and notify a busy state of the target node to the connection unit when the processing result responsive to the command is not returned from the nonvolatile storage device of the target node within the reference time period.

Abstract: Any one of a first storage area and a second storage area, in which redundant data are respectively written, is set as a reference storage area, reference data are read in accordance with a request from the storage area set as the reference storage area between the first storage area and the second storage area, and, when update data are received from an external storage device, information based on the update data is written in the storage area not set as the reference storage area between the first storage area and the second storage area and the information based on the update data is written in the storage area set as the reference storage area.

Abstract: According to one embodiment, a DB integration device includes a receiver and a designator. The receiver is configured to receive at least a request for combining first data and second data. The designator is configured to designate, from among a plurality of DB systems, a DB system for executing a combining process of combining the first data and the second data on the basis of combining capability information. The combining capability information indicates at least one of: whether or not a first DB system is capable of reading the second data from a second DB system and executing the combining process; and whether or not the first DB system is capable of causing the second DB system to read the first data.

Abstract: A database management device, a database management method, and a storage medium capable of improving convenience are provided. A first write manager of a database management device writes data for which a write instruction has been issued from a client to a first storage area of a storage unit. A second write manager writes WAL data corresponding to the write instruction from the client to any address in a second storage area of the storage unit. A determiner determines whether or not to write the WAL data to the second storage area for each transaction process. A transaction manager causes the first write manager to write the data and causes the second write manager to write the WAL data if the determiner determines to write the WAL data and causes the first write manager to write the data if the determiner determines not to write the WAL data.