Abstract: A method and system are provided for maintaining a checkpoint value that indicates which records of a plurality of records associated with updates made before a failure have to be processed after the failure. According to one aspect of the invention, an ordered list of buffers is maintained in volatile memory. The ordered list of buffers has a head and a tail. The ordered list of buffers is maintained by writing a record that indicates the update to nonvolatile memory and adding the buffer to the tail of the ordered list whenever an update is made to a data item within a buffer in volatile memory. When a data item contained in a buffer within the ordered list is stored in nonvolatile memory, the buffer can be removed from the ordered list. A checkpoint value that identifies a record associated with a buffer located at the head of the ordered list is written to nonvolatile memory. According to another aspect, after a failure, the record associated with the checkpoint value is identified.

Abstract: A self monitoring system that identifies optimum summary table(s) for use by a database management system, and that automatically creates or deletes summary tables based on selected summary table recommendations.

Abstract: A system, method, and computer readable-medium for performing operations associated with browser requests are provided. The system includes a plurality of dispatchers coupled to a plurality of web listeners. Each of the dispatchers receives from a corresponding web listener browser requests received by the corresponding web listener. The system further includes a virtual path manager and a resource manager. The virtual path manager is coupled to the dispatchers through an inter-machine communication mechanism. The virtual path manager indicates to the dispatchers which of a cartridges is associated with the browser requests. The resource manager is coupled to the dispatchers through the inter-machine communication mechanism. The resource manager is configured to assign to each dispatcher of the dispatchers an instance of a cartridge of the cartridges in response to receiving a request for an instance from the dispatcher.

Abstract: A method and apparatus allows clients to share ports on a server. The server can maintain more sessions than server ports. When a client sends a command directed to the server, a resource manager inserted between the clients and the server intercepts the command and directs the server to select the session associated with a client prior to or at the same time that the resource manager forwards the intercepted command to the server. Responses from the server are forwarded by the resource manager to the client that sent the command to which the response relates. The resource manager may be coupled to multiple clients, and one or more ports of one or more servers.

Abstract: A method and system for accessing a large object (LOB) that belongs to a cell in a table are provided. An index is built on a column in which the cell resides. The index has a key that includes a LOB identifier. A database server receives from a client a request to access the LOB. The server uses a LOB identifier value for the LOB to traverse the index to locate an index entry for the LOB. The server then follows address information contained in the index entry to a storage containing at least a portion of the LOB and accesses the portion of the LOB as specified in the request. A method and system for tracking storage for data items are also disclosed. Within an index that is built to access the data items are stored both index entries for locating blocks that store current versions of the data items, and index entries for locating blocks that store non-current versions of the data items.

Abstract: A method and system for removing propagation delays between a plurality of database servers that have access to a common database is provided. According to the method, each database server is associated with a logical clock. In response to initiating a commit of a transaction executing on a database server, a commit time for the transaction is determined and broadcast to one or more other database servers. The broadcast is overlapped with a transaction log force. Upon receiving the commit time, the database servers compare the transmitted commit time to the time indicated by their logical clock. If the commit time is greater than the time indicated by their logical clock, the database server sets its logical time to reflect a time that is at least as recent as the time reflected by the transmitted commit time.

Abstract: A virtual bookshelf system provides a user a way to browse and locate information associated with a plurality of documents. The virtual bookshelf system contains classification information to classify the documents in a hierarchical structure that includes a plurality of hierarchical levels based on pre-defined categories. The virtual bookshelf system displays a portion of the hierarchical structure including a representation of the categories. A user of the virtual bookshelf system may browse through the categories in the hierarchical levels to learn the general topics of the available documents. The user is permitted to select a particular category, and in response, the virtual bookshelf system displays document information for documents classified in the category selected. When selected, peripheral themes or issues are displayed such that the themes relate to the main issues covered by the documents classified under the selected category.

Abstract: An object, such as a relational database table, is partitioned into a plurality of subsets. Selected subsets, e.g. partitions, of the object are exported into a dump file, identifying each exported subset of data by writing a marker in the dump file. Selected subsets are imported from the dump file, by determining whether the marker in the dump file corresponds to the selected subsets, then conditionally importing the data associated with the marker. Objects are repartitioned by exporting the some of the subsets, reconfiguring the object, and importing the exported subsets back into the object.

Abstract: A method and an apparatus for managing access to data on a distributed database system is provided. A snapshot list is generated for a transaction executing on the distributed database system. The snapshot list specifies snapshot times for a plurality of locations in the distributed database system. The snapshot times are determined based upon the location of a data item and the location where the transaction is executing. The selection of a version of the data item to be provided to the transaction is made based upon the snapshot time for the location associated with the data.

Abstract: An apparatus and method for accessing foreign processes in a heterogeneous database environment includes a local database server having a heterogeneous services module to selectively send requests to the foreign processes based on their respective capabilities. A client application sending a statement to the local database server is checked by the local server process to determine if the statement includes a reference to a foreign database system, or whether the statement is registered as an external routine. The heterogeneous services module selectively outputs a request to an agent process executing in an address space separate from the local server process and in communication with the foreign database. The agent process performs all necessary interaction with the foreign database, including data type translation.

Abstract: A method and apparatus are provided for allowing a resource manager to be more tightly integrated with foreign transaction managers with which it interacts through the use of an extensible framework of transaction and resource manager events. The tighter integration made possible by a framework in which personality modules are registered with resource managers. Each personality module corresponds to a particular foreign transaction protocol. Each personality module includes a mapping of key resource and transaction events to actions, where the action mapped to a particular event is the action required by the protocol in response to the event. When an event occurs within the resource manager, the resource manager performs the action mapped to the particular event by the appropriate personality module.

Abstract: A method and apparatus are provided for allocating buffer memory for database sort operations. A database parameter is set to determine whether and how direct write buffers are to be allocated for sort operations. If the parameter is set to a first value, then direct write buffers will be used to perform writes to disk. The size and number of direct write buffers to be used will be determined by the values set in other database parameters. If the parameter is set to a second value, then no direct write buffers will be used, and sort operations will write to disk through a buffer cache. If the parameter is set to a third value, direct write buffers will be allocated a portion of the memory available to perform the sort operation. The size and number of direct write buffers will be determined in accordance with database formulae that are designed to optimize sort and data write performance.

Abstract: A method and apparatus are provided for processing reports. Upon system startup, a report server automatically starts one or more report processes. As client report commands are received from one or more client applications, the client report commands are assigned to one or more of the executing report processes. After a report is completed, the report process is automatically reinitialized and kept active to process another report. The report server automatically adjusts the number of active report processes based on the current report processing load requirements. According to another aspect of the present invention, a report queue is provided to store client report commands as they are received from the client applications. A report queue manager is also provided for externally managing the report queue.

Abstract: An apparatus and method for accessing foreign processes in a heterogeneous database environment includes a local database server having heterogeneous services to selectively send requests to the foreign processes based on their respective capabilities. A client application sending a statement to the local database server is checked by the local server process to determine if the statement includes a reference to a foreign database system. The local server process selectively outputs a request to an agent process in communication with a foreign database via a generic Application Programming Interface (API). The request output to the foreign database is based on accessing a capabilities table specifying the operations that can be executed by the foreign database.

Abstract: A record management system provides for displaying a two-pass value measure result in a multi-dimensional view containing cells. The record management system identifies a set of cells in the multi-dimensional view. The set of cells includes all cells needed for determining the two-pass value measure result. The record management system determines a one-pass value for each cell in the set of cells. Based on the one-pass values, the record management system determines the two-pass value measure result.

Abstract: A binary hyperspatial code (BH code) is generated for each row in a table to be partitioned. An intermediate table containing the BH codes and rowids of the original table is created within the database. The intermediate table allows for efficient database operations to be performed to determine how to partition the table without causing the data in the table to go off-line. After the desired partitions have been identified from accessing the intermediate table, the table is subdivided into the desired partitions. In one embodiment, the partitions are stored as index-organized tables index on the BH codes so that rows that are close together (as defined by the BH codes) are likely to be located in the same disk block.

Abstract: A method is disclosed that involves establishing a transaction stack in a memory of a computing system that is processing transactions. Two commands, PUSH and POP, operate on the stack. The PUSH command causes a frame of data identifying the currently executing transaction to be pushed onto the transaction stack. After a PUSH is executed, the first transactional statement that executes causes creation of a new autonomous transaction. If another transactional statement is executed after the new transaction commits or rolls back, but before a POP is executed, then another new autonomous transaction is created. A POP operation restores the transaction identified by the top frame of the stack. In another aspect, a programming language construct is provided for associating a lexical scope with an autonomous transaction scope. When the lexical scope is first entered during execution of the program in a first transaction, the transaction context of the first transaction is stored on a transaction stack.

Abstract: The present invention provides a method and apparatus for processing electronic mail in parallel. The present invention provides the ability to process mail objects in an electronic mail system in parallel. A message can be assigned to a queue. One or more processes can manage a plurality of messages in the queue. Each process can identify the next entry to be processed. Entries previously processed can be marked such that subsequent access is locked out. Mail objects and process information can be stored in a relational database system that provides the ability to perform locking at the record level. A process can be configured to perform a plurality of activities in a plurality of time periods. A guardian process can initiate or terminate other processes based on process information. Further, a guardian process examines system information periodically and identifies any need to initiate, restart, or stop one or more processes.

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 packaging system is provided for shipping optical media, such as compact discs (CDs), digital video discs (DVDs), and compact disc recordables (CDRs), in an environmentally responsible and cost effective manner. The packaging system's construction uses primarily recyclable material and requires far less raw material than other shipping packaging options. The packaging system is also lightweight and suitably durable for passage through the normal shipping channels, such as the United States Postal Service. The packaging system may be easily configured to accommodate different numbers of optical media discs.