| 摘要 |
Data is separated from source. Datasets store tables of data and a graph of the relationships between the tables. The relationship can change at any time. The relationships are described by metadata that describe primary key, foreign key, and lookups, and other relationships between tables. In one embodiment, the tables of data are typed columns of data. The dataset also includes information on the rowstate and differential preservation, therefore, the source does not need to manage states of the data access. Adapters abstract the interface to datasets. More specifically, adapters manage the input/output to the datasets of the tables of data and the relationships. Adapters can be specialized in their purpose, such as an adapter for OLE data or XML data or generalized in their purpose. Furthermore, a composite adapter is specialized for the purpose of interacting with other adapters. Adapters manage the connection to the dataset and the name of the server that hosts the dataset. Data hoisting is implemented, in which the fluid relationship of data is changed in response to current data needs.
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