Abstract: An XML representation of the metadata for objects in a database system. The XML representation is called SXML. The SXML representations of two objects that belong to the same class of objects may be compared to produce a difference representation that shows the differences between the objects. Database commands that will create or alter objects may be produced from the difference representation, as well as an XML representation of the database commands. In addition to being comparable, SXML representations have the characteristics that a given property of the metadata is expressed in only one way in the representation, that SXML does not describe properties that belong only to particular instances of the object described by the metadata, that SXML describes only properties that the user can specify when creating an object, and that SXML is easy for humans to read, understand, and write.

Abstract: Techniques for transferring objects between database systems. A transfer is controlled by a master table in the RDBMS that is performing the transfer operation. The master table specifies the kind of transfer operation to be performed, a set of objects to be transferred, operations to be performed on the objects as they are being transferred, and filters for selecting a subset of the objects. During execution of the transfer, the transfer mechanism maintains and updates state in the master table and thereby makes it possible for the entity that is doing the transfer to determine the current status of the transfer and to restart the transfer after it has been stopped. The entity that is performing the transfer may also detach from the transfer without stopping the transfer and later again attach to the transfer.

Abstract: An XML representation of the metadata for objects in a database system. The XML representation is called SXML. The SXML representations of two objects that belong to the same class of objects may be compared to produce a difference representation that shows the differences between the objects. Database commands that will create or alter objects may be produced from the difference representation, as well as an XML representation of the database commands. In addition to being comparable, SXML representations have the characteristics that a given property of the metadata is expressed in only one way in the representation, that SXML does not describe properties that belong only to particular instances of the object described by the metadata, that SXML describes only properties that the user can specify when creating an object, and that SXML is easy for humans to read, understand, and write.

Abstract: A method for extracting metadata for plural related objects of different types from a database includes defining a heterogeneous object type as a collection of database objects of different types. Upon a request to fetch a particular heterogeneous object, member objects of the heterogeneous object are fetched from the particular heterogeneous object in a specific order based on the definition of the heterogeneous object's type, such as a valid order for re-creating the particular heterogeneous object. The set of member objects to be fetched can be restricted according to at least one specified filter, which itself may be translated into a second filter according to a type of a member object being fetched. Such translated filters can inherit values from the filter specified in the request for the particular heterogeneous object type, or can have a fixed value of some data type. The extracted metadata can be formatted to recreate the particular heterogeneous object.

Abstract: A method for extracting metadata for plural related objects of different types from a database includes defining a heterogeneous object type as a collection of database objects of different types. Upon a request to fetch a particular heterogeneous object, member objects of the heterogeneous object are fetched from the particular heterogeneous object in a specific order based on the definition of the heterogeneous object's type, such as a valid order for re-creating the particular heterogeneous object. The set of member objects to be fetched can be restricted according to at least one specified filter, which itself may be translated into a second filter according to a type of a member object being fetched. Such translated filters can inherit values from the filter specified in the request for the particular heterogeneous object type, or can have a fixed value of some data type. The extracted metadata can be formatted to recreate the particular heterogeneous object.

Abstract: Techniques for simplifying the aggregation of data stored in a number of objects in a database system. A user-defined type and an object view are associated with a kind of data to be aggregated. The object view specifies the locations of the data in the objects and maps the data to be aggregated into the user-defined type. An application program interface includes a fetch interface that causes the database system to make a query over the object view associated with the kind of data and return the aggregated data in a set of objects of the user-defined type. The returned data is converted to XML and may be further transformed using XSL stylesheets.

Abstract: A method for extracting metadata for plural related objects of different types from a database includes defining a heterogeneous object type as a collection of database objects of different types. Upon a request to fetch a particular heterogeneous object, member objects of the heterogeneous object are fetched from the particular heterogeneous object in a specific order based on the definition of the heterogeneous object's type, such as a valid order for re-creating the particular heterogeneous object. The set of member objects to be fetched can be restricted according to at least one specified filter, which itself may be translated into a second filter according to a type of a member object being fetched. Such translated filters can inherit values from the filter specified in the request for the particular heterogeneous object type, or can have a fixed value of some data type. The extracted metadata can be formatted to recreate the particular heterogeneous object.