Abstract: A system, method, computer program and system for suspending a result set and continuing from a suspended result set for a scrollable cursor is disclosed. The rows from a row source corresponding to the scrollable cursor result set are suspended into storage so that when a fetch is requested the data can be sent (continued) from the suspended storage and does not depend on the original scrollable cursor row source or session to be available.

Abstract: An object type translator (OTT) determines one or more database object types. The one or more database object types are mapped to a first structural language type definition code. After being generated, the user may add user code to the first structural language type definition code. During regeneration of these files, the first structural language type definition code is then parsed to determine the user code that has been added, based on the start and end markers that the user code segments have been marked with. OTT maps these user-code segments to the corresponding database types and keeps track of the mapping and the user code. When the OTT starts generating the second structural language code, the OTT determines a position where the user code should be inserted into the second structural language type definition code using that mapping. The user code is then inserted in the second structural language code in the position determined.

Abstract: A method and system for implementing scrollable cursors is described. A multi-tier caching structure is maintained, in which a partial result set is cached at the client computer and a more-complete result set is cached at the server computer. If the cursor is scrolled in either the forward or backward directions, the partial result set cached at the client computer is first checked to see if requested data is present. If so, then the requested data is fetched from the client cache and the current position of the cursor is moved to the appropriate position in the result set. If the requested data is not present in the client cache, then those data items are fetched from the cache at the server computer.

Abstract: Files of software to be installed in a computer are packaged as follows. A source file is prepared to contain at least a declaration of an array of sufficient space to accommodate the files to be packaged. The source file is compiled into an executable file. Thereafter, the array in the executable file is overwritten with data from each file being packaged. Depending on the embodiment, the address of where each file begins in the executable file and each file's name may be stored in the same executable file or in a different file. The stored file names are used to identify an address of a file from its name, when the named file is first accessed. In several embodiments, the operating system loads the executable file as a library that is automatically shared by multiple instances of the application (or by multiple applications), to efficiently use physical memory.

Abstract: Schema conversion approaches convert images of complex objects. The schema conversion is performed on images of complex objects belonging to a root class, whether those objects are instances of the root class or instances of a subclass of the root class. A complex object is an object that is comprised of a collection of objects or that has another object as an attribute. The approaches use change vectors to represent changes to make to an image to convert it between the target schema version and source schema version. Change vectors are generated based on schema version records, each of which describes the properties of a schema version, including the attributes in the schema version and the data type of each of the attributes. The approaches evolve changes that includes addition, modification and deletion of object attributes. They convert from an earlier schema version to a later schema version, and vice versa, i.e. from a later schema version to a earlier schema version.

Abstract: A method for providing memory management for objects is described. Specifically, techniques are described for providing common memory management code to objects that are instances of different classes and for releasing a memory management subtree that starts with a particular object in the memory management tree. A memory management template provides common pre-processor memory management code. A specialized version of the memory management template is used to create a specialized template subclass. When a memory management operator of an object that is an instance of the specialized template subclass is invoked the common memory management code in the specialized template is executed. Memory is associated with each object in a hierarchical tree. Data for the memory is maintained that reflects the hierarchical tree relationship between the objects. A subtree and the associated memory can be released without an application program tracking the relationships.

Abstract: One embodiment of the present invention provides a system that facilitates transactional consistency for references in an object-relational database. The system operates by first receiving a reference to an object located in the object-relational database. Next, the system creates a reference object within local storage that includes an object descriptor to indicate whether the object has been loaded into local storage. The reference is stored in this reference object. A pointer within an application program can then point to the reference object, so that the application program can use the pointer to access the object.

Abstract: A method and system for implementing failover in a computer system is provided. For a failover involving an order-sensitive dataset or application, a mechanism is provided to detect order inconsistencies between a first set of data and a second set of data, in which the first set of data corresponds to a first connection established before the failover and the second set of data corresponds to a second connection established after the failover.

Abstract: An improved method, mechanism, and system for implementing, generating, and maintaining for implementing session pools is disclosed. A session in a session pool can be customized to with a specific set of affinities and attributes. Tags can be associated with the customized sessions. When a later request is made for a session having a set of desired characteristics, the tags can be used to search for and identify a session in the session pool having the requested characteristics. Also disclosed is a method, mechanism, and system for dynamic sizing of session pools.

Abstract: An improved method, mechanism, and system for implementing, generating, and maintaining for implementing session pools is disclosed. Disclosed is a method, mechanism, and system for dynamic sizing of session pools, in which the number of sessions in a given session pool or sub-session pool can be dynamically adjusted upwards or downwards. Also disclosed is an approach for customizing a session in a session pool with a specific set of affinities and attributes, in which tags can be associated with the customized sessions. Tagging can be used to identify sessions to deallocate/reallocate to dynamically size the session or sub-session pools.

Abstract: Memory for complex objects is maintained in pools of dynamic memory on a “per-duration” basis. Each duration is assigned its own area or areas of the heap, and all the memory allocation for a specific duration comes from those assigned areas of the heap. Memory allocation for a complex object is performed with respect to a single duration and, hence, memory is allotted for the complex object from the corresponding memory pool. When a duration is terminated, the memory allocated for its corresponding heap is freed, thereby releasing memory for all the complex object using the memory from the memory pool for that duration. Management of other resources for complex objects such as opening and closing files may also be duration-based. In one aspect, the memory management of complex objects is located in an automatically generated client stub routine for a remote procedure call.

Abstract: A method and apparatus that allow schema version evolution to occur without requiring applications that expect older schema versions to be recompiled is provided. According to one aspect of the invention, each application that requests data is supplied the data in the format that the application expects. To supply the data in the expected format, a mechanism is provided for tracking the evolution of data types without losing information. In addition, mechanisms are provided for determining the format expected by the application and the format in which the data is currently stored. A mechanism is also provided for converting the data from the stored format to the expected format when the two formats do not match. A data migration strategy is described in which data is gradually migrated to newer formats when the data is updated by applications that expect a more recent format than the format in which the data is currently stored.

Abstract: A method and apparatus that allow schema version evolution to occur without requiring applications that expect older schema versions to be recompiled is provided. According to one aspect of the invention, each application that requests data is supplied the data in the format that the application expects. To supply the data in the expected format, a mechanism is provided for tracking the evolution of data types without losing information. In addition, mechanisms are provided for determining the format expected by the application and the format in which the data is currently stored. A mechanism is also provided for converting the data from the stored format to the expected format when the two formats do not match. A data migration strategy is described in which data is gradually migrated to newer formats when the data is updated by applications that expect a more recent format than the format in which the data is currently stored.

Abstract: The present invention pertains to an apparatus and process for storing information object collections in a database. Examples of such object collections are nested tables and variable length arrays. In an embodiment, the invention provides mechanisms and methods for storing nested tables in either a base table of a database, or an index-organized table. In one embodiment, mechanisms and methods are provided for storing variable length arrays into a table column, as a large object ("LOB"), or as an index-organized table. The invention also provides methods and mechanisms for accessing data from these storage mediums.