发明授权
- 专利标题: Opaque types
- 专利标题(中): 不透明类型
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申请号: US09629541申请日: 2000-07-31
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公开(公告)号: US06470348B1公开(公告)日: 2002-10-22
- 发明人: Rajagopalan Govindarajan , Viswanathan Krishnamurthy , Anil Nori
- 申请人: Rajagopalan Govindarajan , Viswanathan Krishnamurthy , Anil Nori
- 主分类号: G06F1730
- IPC分类号: G06F1730
摘要:
A method and apparatus are provided for handling within a database system data items that are associated with data types whose native structure is not known to the database system. The data items are stored within the database system in their native structure, even though it is not understood by the database system. To store the data items, the database system calls a pickling routine that is provided by the user, or by the runtime subsystem of the programming environment that is native to the data item. To retrieve the routine from storage, the database system calls an unpickling routine, also provided by the user or the appropriate runtime subsystem. Because the database maintains the data items in their native format, no conversions are required as the data items are passed between the database system and external routines that manipulate the data items. Techniques are also provided for declaring attributes of the data item that can be accessed within the database system. The user provides routines for the database system to call in order to access the declared attributes, which may be different than the actual attributes that the data item has in its native environment.