公开(公告)号：US20060161530A1

公开(公告)日：2006-07-20

申请号：US11039528

申请日：2005-01-19

申请人： Dilip Biswal ,  Isaac Cheng ,  Cecilia Chu ,  Donald Clare ,  Louis Mau

发明人： Dilip Biswal ,  Isaac Cheng ,  Cecilia Chu ,  Donald Clare ,  Louis Mau

IPC分类号： G06F7/00

CPC分类号： G06F17/30309 ,  G06F17/30353 ,  G06F17/30356 ,  Y10S707/99932 ,  Y10S707/99933 ,  Y10S707/99953

摘要： A method and system for efficient snapshot querying include: providing a first version value for each data in a history table, where the first version value indicates a beginning of a period in which the data is valid; providing at least a second version value for each data in the history table, where the second version value indicates an end of the period in which the data is valid; receiving a request for a version of a database; and retrieving the data with the first version value less than or equal to the requested version and the second version value greater than or equal to the requested version. By maintaining a history table with redundant version information, the method and system are able to provide efficient snapshot querying while also avoiding the overhead burden of conventional approaches. No aggregates, joins, or sub-queries are required to retrieve a snapshot.

公开(公告)号：US20060161606A1

公开(公告)日：2006-07-20

申请号：US11039472

申请日：2005-01-19

申请人： Dilip Biswal ,  Isaac Cheng ,  Cecilia Chu ,  Donald Clare ,  Louis Mau

发明人： Dilip Biswal ,  Isaac Cheng ,  Cecilia Chu ,  Donald Clare ,  Louis Mau

IPC分类号： G06F17/30

CPC分类号： G06F17/30356 ,  G06F17/30575 ,  H04L67/1095 ,  Y10S707/99953 ,  Y10S707/99955

摘要： An improved method and system for synchronization-replication concurrency maintain a history table for a data table in a mirror, where the history table can include redundant version values that indicate a period in which data values corresponding to the version values are valid. Replication can thus be performed between a source and a mirror for a current version of the data table, while synchronization is simultaneously performed between the mirror and a client for an earlier version of the data table using the history table. Simultaneous reads, writes, and read-writes are possible while maintaining data reliability. The replication and synchronization processes can be performed at the read-uncommitted isolation level to increase efficiency. The method and system thus increase overall data throughput, reduce client response time, and dramatically enhance end-user satisfaction.

摘要翻译： 用于同步复制并发的改进的方法和系统维护镜像中的数据表的历史表，其中历史表可以包括指示对应于版本值的数据值有效的周期的冗余版本值。 因此，可以在数据表的当前版本的源和镜像之间执行复制，同时使用历史表在镜像和客户端之间同时执行数据表的早期版本的同步。 在保持数据可靠性的同时，可以进行同时读取，写入和读写操作。 可以在读取未提交的隔离级别执行复制和同步过程，以提高效率。 因此，该方法和系统可以提高整体数据吞吐量，减少客户响应时间，并显着提升最终用户的满意度。

公开(公告)号：US20060101212A1

公开(公告)日：2006-05-11

申请号：US10985421

申请日：2004-11-10

申请人： Dilip Biswal ,  Isaac Cheng ,  Cecilia Chu ,  Donald Clare ,  Louis Mau

发明人： Dilip Biswal ,  Isaac Cheng ,  Cecilia Chu ,  Donald Clare ,  Louis Mau

IPC分类号： G06F12/00

CPC分类号： G06F17/30578 ,  Y10S707/99952 ,  Y10S707/99953

摘要： A method and system for synchronizing data on a first device with data at a second device, includes: determining a pre-image of the data on the first device according to a filter after a previous synchronization with the data at the second device; determining a current image of the data at the second device according to the filter; determining a delta of the current image, where the delta comprises data that exists in the current image and has changed since the previous synchronization; instructing the first device to delete data that exists in the pre-image but not in the current image; and instructing the first device to UPSERT a union of the data that exists in the delta and the data that exists in the current image but not the pre-image. This is efficient in time and bandwidth resources while also providing consistent data integrity.

摘要翻译： 一种用于将第一设备上的数据与第二设备上的数据同步的方法和系统，包括：在先前与第二设备之间的数据同步之后，根据过滤器在第一设备上确定数据的前图像; 根据滤波器确定第二设备处的数据的当前图像; 确定当前图像的增量，其中所述增量包括存在于当前图像中并且自先前同步之后已经改变的数据; 指示第一设备删除存在于前图像中但不在当前图像中的数据; 并指示第一个设备对存在于增量中的数据和当前图像中存在的数据而不是预映像进行联合。 这在时间和带宽资源方面是有效的，同时也提供一致的数据完整性。