Abstract: A database server for implementing a distributed database, the server having access to a data store holding a first copy of the database managed by the database server and having a processor and interfacing means for client communication and for communication with a second database server managing a second copy of the database, the database server may implement a change to the database communicated from the client by the steps of: communicating the change to the second database server; storing in the first copy of the database a tentative record of the change; and on receiving from the second database server a storing record acknowledgement about the change in the second copy of the database: instructing the second database server to store a permanent record of the change in the second copy of the database and storing in the first copy of the database a permanent record of the change.

Abstract: A log-structured storage method and a server, where the method includes obtaining a current incremental update of an object when the object is updated, wherein a current version of the object is stored in a log-structured storage area of the server, determining whether there is a previous incremental update of the object stored in the log-structured storage area, writing the current incremental update as a latest incremental update in the log-structured storage area when there is no previous incremental update of the object stored in the log-structured storage area such that the utilization of memory can be improved.

Abstract: A data storage device is provided, comprising a control module a first storage module a second storage module a third storage module and a buffer. The first storage stores a plurality of data sets. The control module receives requests for operations to be carried out on the plurality of data sets in the first storage module, executes the received requests and copies the plurality of data sets in the first storage module to the second storage module at a predetermined time. The control module further adds the received requests for operations to the buffer and persists the buffer to the third storage module by a synchronization means. The data storage device initializes the plurality of data sets in the first storage module from the second storage module and carries out operations corresponding to the requests from the third storage module in a recovery scenario.

Abstract: A log-structured storage method and a server, where the method includes obtaining a current incremental update of an object when the object is updated, wherein a current version of the object is stored in a log-structured storage area of the server, determining whether there is a previous incremental update of the object stored in the log-structured storage area, writing the current incremental update as a latest incremental update in the log-structured storage area when there is no previous incremental update of the object stored in the log-structured storage area such that the utilization of memory can be improved.

Abstract: A method and an apparatus of maintaining data for online analytical processing in a database system. The method includes: tracking a changed page in a main process; and synchronizing the changed page to a child process for online analytical processing. In the method and apparatus of maintaining data for online analytical processing, the changed pages are tracked and then the child process is synchronized with the changed pages. Therefore, periodic forking is avoided, fork overhead due to periodic forking in the prior art is removed, the synchronization is faster since only the changed pages are synchronized, and the performance of online data processing is enhanced.

Abstract: A data storage device is provided, comprising a control module a first storage module a second storage module a third storage module and a buffer. The first storage stores a plurality of data sets. The control module receives requests for operations to be carried out on the plurality of data sets in the first storage module, executes the received requests and copies the plurality of data sets in the first storage module to the second storage module at a predetermined time. The control module further adds the received requests for operations to the buffer and persists the buffer to the third storage module by a synchronization means. The data storage device initializes the plurality of data sets in the first storage module from the second storage module and carries out operations corresponding to the requests from the third storage module in a recovery scenario.

Abstract: A method and an apparatus of maintaining data for online analytical processing in a database system. The method includes: tracking a changed page in a main process; and synchronizing the changed page to a child process for online analytical processing. In the method and apparatus of maintaining data for online analytical processing, the changed pages are tracked and then the child process is synchronized with the changed pages. Therefore, periodic forking is avoided, fork overhead due to periodic forking in the prior art is removed, the synchronization is faster since only the changed pages are synchronized, and the performance of online data processing is enhanced.

Abstract: A data persistence processing method is disclosed, where the method includes: adding the dirty page identifier to a checkpoint queue each time when a dirty page is generated in a database system memory; determining an active group and a current group in the checkpoint queue, and successively dumping, to a disk, the dirty pages corresponding to the active group on a preset checkpoint occurrence occasion, where the dirty pages are currently prepare to be dumped to the disk, and a group inserted with a dirty page that is newly added is the current group; and determining a next active group if last dumping is completed, and successively dumping, to the disk, the dirty pages corresponding to the next active group on the checkpoint occurrence occasion. The method improves the dumping efficiency of the dirty pages.