tailieunhanh - Hướng dẫn học Microsoft SQL Server 2008 part 81

Framework là mỗi nhà cung cấp có thể khác nhau, trong đó một trong những nhà cung cấp không thực sự quan tâm về các loại dữ liệu khác của các cửa hàng hoặc nhà cung cấp. Điều này là tất cả các xử lý bởi các phiên đồng bộ. Khi một phiên họp diễn ra đồng bộ hóa dữ liệu giữa một kho dữ liệu nguồn và đích lưu trữ dữ liệu một được trao đổi bằng cách kết nối một nhà cung cấp nguồn với một nhà cung cấp đích. . | PartV Data Connectivity Framework is that each provider can be different in that one provider does not really care about the other types of data stores or providers. This is all handled by the sync session. When a synchronization session takes place data between a source data store and a destination data store are exchanged by connecting a source provider with a destination provider. As synchronization takes place the destination provider supplies its current state to the sync session. At that point it accepts a list of changes from the source detects any conflicts between the data it just received and its own data and then applies any changes to its own data store. Sync knowledge A term that you should remember when working with the Sync Framework is the concept of sync knowledge. Knowledge is metadata. It is the information that the Sync Framework algorithms use to utilize change enumeration and conflict detection. The metadata describes each and every change that has been or will be applied to a data store via synchronization or applied directly. Thus knowledge assists in the following Change enumeration The process of resolving changed items that is resolving which items have been changed on the source data store that have not been applied to the destination data store thus the destination data store does not have knowledge of the source data store changes . Conflict detection The process of obtaining synchronization conflicts. A synchronization conflict happens when an operation was made by one data store and knowledge of that change was not transferred to the other data store. Now with that in mind it is important to understand that neither an application nor a synchronization provider uses sync knowledge directly. Nor should it. That is the job of the Sync Framework. The Sync Framework will call the necessary methods to initiate operations for them. However it is also important to understand how sync knowledge works so this section briefly describes sync .