Abstract: A method and system for associating properties in a computer system is described. An aspect relates to a mechanism for dynamically determining the value of a property for an instance or object, which can override the property defined for the class or object type. Another aspect relates to a mechanism for dynamically changing at run-time the set of properties associated with system structures, such as classes, object types, instances, or objects. Yet another aspect relates to a mechanism that can associate or disassociate an entire set of properties at the same time, rather than having to separately associate or disassociate each property within a set of properties. A further aspect relates to a mechanism for allowing particular instances or objects to explicitly not inherit properties of its familial class or object type.

Abstract: A method and system for optimizing the execution of database statement is described. An aspect is related to providing a framework for the creation, association, and use of optimizer-related functions to calculate the cost of execution plans involving non-native database entities. Examples of these optimizer-related functions include selectivity, statistics, and costs functions. Another aspect is related to the optimization of database statements having non-boolean predicates. Yet another aspect is related to the determination and use of different granularity levels of information for submitting database statement predicates to optimizer-related functions. Optimizer-related functions can also be defined for system-supplied objects and entities.

Abstract: 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.