Abstract: A method, apparatus, and article of manufacture for query simplification by applying generalized inference propagation and generalized transitive closure in SQL queries having selection, projection, join, outer join, and intersection operations. The disclosed transformations and enumeration method unify and solve the problems of 1) unnesting join aggregate queries, and 2) complete enumeration of queries containing outer joins, when the outer join predicate references an aggregated value, or the predicate references more than two base relations in a query subtree. The system first eliminates redundant sub-expressions and modifies expensive binary operations to inexpensive binary operations, then converts complex predicates to simple predicates by application of a generalized selection (GS) operator.

Abstract: A system for effecting communications between a computing device and a plurality of peripheral devices which comprises a bus controller for controlling the communications, a plurality of feedback generator circuits for providing operational status information, each of the plurality of peripheral devices having an associated one of the plurality of feedback generator circuits. The system further comprises a bus for conveying signals between the bus controller and the plurality of peripheral devices. In the preferred embodiment, each of the plurality of peripheral devices has a respective address and each of the plurality of feedback generator circuits contains the operational status information for its respective peripheral device.

Abstract: A partially relocated object identifier store including "copy from" and "copy to" identifier storage accessible to write and read barrier logic allows the write and read barrier logic to selectively direct store- and load-oriented accesses to an appropriate FromSpace or ToSpace instance of a partially relocated memory object, in accordance with the memory object's partial relocation state. In some embodiments, the barriers trap to a partially relocated object trap handler. In other embodiments, the write barrier itself directs accesses without software trap handler overheads. Optional "how far" indication storage facilitates differentiation by the barrier logic, or by the partially relocated object trap handler, between a copied portion and an uncopied portion of the partially relocated memory object.

Abstract: A speed and memory control system and method for use with a sort accelerator having a rebound sorter and merger is disclosed. The speed and memory control system includes a variable length shift register which utilizes circulating RAM indexing, tag extraction lookahead features to speed up access of records, and merge lookahead and memory management features to provide quick and effective storage of records.

Abstract: In order to provide communication between two processors in a data processing system, a target processor includes apparatus that can store data signal groups from a source processor. Having stored a data signal group from the source processor, the target processor notifies the source processor of the receipt of the data signal group. In response to the presence of the stored data signal group, the target processor executes a interprocessor command or instruction identified by the transferred data signal group. The source processor at a preselected time, executes an instruction to determine if the command designated by the data signal group stored in the target processor has been executed. The commands specified by the transferred data signal groups can be executed under hardware control by the target processor in a relatively short time immediately following completion of the instruction in execution in the target processor at the time of the transfer of the data signal group.

Abstract: The present invention is embodied in new priority queue data structures for event list management of computer simulations, and includes a new priority queue data structure and an improved event horizon applied to priority queue data structures. The new priority queue data structure is a Qheap and is made out of linked lists for robust, fast, reliable, and stable event list management and uses a temporary unsorted list to store all items until one of the items is needed. Then the list is sorted, next, the highest priority item is removed, and then the rest of the list is inserted in the Qheap. Also, an event horizon is applied to binary tree and splay tree priority queue data structures to form the improved event horizon for event management.

Abstract: The present invention synchronizes threads in a garbage-collected system. In accordance with the invention, each thread may enable or disable garbage collection. A synchronization facility receives a request to initiate garbage collection. In response to the request, the facility identifies threads that have enabled garbage collection more recently than they have disabled garbage collection. Then, until all of the threads are identified or suspended, the facility identifies threads that enable garbage collection and suspends threads that disable garbage collection. When all threads are identified or suspended, the facility performs garbage collection. The facility also suspends any identified threads that attempt to disable garbage collection during the performance of garbage collection.

Abstract: A class signature interface exposes members of an object class in an object oriented software system by exposing access information to the member. The class signature interface has application for use with object models that require client objects to utilize the functionality of server objects through interfaces, such as required by the Component Object Model (COM). Class signature interfaces expose interfaces supported by the object class to provide time constant access to the interfaces of the object class. The class signature interfaces also expose attributes and methods, defined directly on the class level. The class signature interface has further application for use in an object oriented software system to add additional class members to an object class without adding the class members to a separate interface.

Abstract: Portable electronic devices containing user's calendars have proliferated. Similarly, files, web pages, databases and information sources have become commonplace. The present invention combines knowledge of the current date and time with knowledge of entries in the user's calendar to automatically generate queries against those files, databases and information sources. The results of those queries are then made available to the user in order to provide the user with additional information about the subject of the meeting, the other attendees, their employers, etc. The present invention connects multiple devices together in a passive information retrieval model, leveraging off of mobile, desktop, and server systems, context data and search and retrieval technology. The present invention is thus an automatic search and retrieval system providing its user with relevant information to a scheduled meeting or event.

Abstract: The system and apparatus for loading and retrieving information relates to a computer-implemented database management system for multiple source databases. The system also has a variety of database management tools. The system uses hierarchical, network, and relational structures to establish and maintain relationships between disparate categories of information in multiple records or databases within the system. Data entered into the system are stored in a common data repository in disk memory, which categorizes each source field independent from the source record definition. Separating the source record definition from the fields within each source record definition allows data to remain independent from the original structure of the information. Yet, source record definitions are maintained to show the relationships between data from different fields. The system allows all data to be referenced by any number of methods without regard to how the data was entered into the system.

Abstract: When recording a large volume of data such as video data, audio data, or the like, it is desirable to delete menus for unnecessary files and thereby enable quick and efficient access to data. An optical recording medium having a data recording medium which is divided into at least a readable/writable first region and a second region used exclusively for data reading. The first region has recorded therein a title management information table in which filenames of software titles are registered in the second region, and a loader for executing or reproducing these software titles, wherein the loader and the software title correspond to each other. The second region has recorded therein at least two types of software titles.

Abstract: A method and apparatus for operating parallel databases in a multi-processor computer system. Client Applications interact with a Navigation Server executing on the computer system, and through it, with one or more Data Servers. The Navigation Server receives requests from the Client Applications, which it compiles or translates into a plurality of parallel SQL statements. These parallel SQL statements are communicated to particular ones of the Data Servers for execution. The Data Servers, each of which may execute on different processors in the computer system, perform their respective SQL statements and thus access their database partitions concurrently and in parallel, thereby reducing the overall access time of a given request from a given Client Application. The computer system behaves, and is presented to users, as if the database resides under the control of a single Data Server, even though the database is partitioned across multiple Data Servers.

Abstract: A system and method for implementing database cursors at the server in a client/server environment is disclosed. In operation, the system and method for implementing the database cursors is compatible with existing client/server database search engines but provides for increased control over cursor lock options, an ability to share cursors and search plans across multiple nodes in a network, and an increase in the overall operating efficiency of a database application. The invention is directed to cursors for all types of collections or compilations of data in a client/server database environment.

Abstract: A log device based data storage subsystem provides for the efficient storage and retrieval of data with respect to an operating system executing on a computer system coupled to the data storage system. The data storage system includes a storage device providing for the storage of predetermined file and system data, as provided by the computer system, within a main filesystem layout established in the storage device. The data storage system also includes a log device coupled in the logical data transfer path between storage device and the computer system. The log device provides for the storage of the predetermined file and system data within a log structured filesystem layout established in the log device.

Abstract: In a client/server computing system, a method and apparatus for efficiently storing entries in a log file during disconnected client operations. An encoder utilizes a log file and a write file table for logging the write operations performed by the client during disconnected operations. The logging method employed by the encoding module logs in the log file only writes associated for different files. The encoding module tracks the status of the entries in the log file with a write file table containing the most recent sequence number associated with a file entry of the log file. Upon reconnection of the client to the server, a decoding module replays the events in the correct chronological order by transferring the file data modified during the period of disconnection in the order dictated by the write file table. A deferred write list is accessed by the decoding module for temporary storage any write operations whose replay should be delayed to preserve the relative order of events.

Abstract: A file access history attribute may be encoded and stored with a file in a computer memory. The file access history attribute may provide information as to the date of most recent access and the level of access on which date. In addition, the file access history attribute may provide information concerning recent file history (e.g., previous nine days), quarterly history (e.g., 80 days preceding the previous nine days), as well as long-term history (e.g., beyond the 80 day period). The encoding technique of the present invention may compress file access history information into a compact file access history attribute (e.g., six to twelve bytes). Disk caching software, for maintaining files in a hard drive of a local computer coupled to a network, may utilize the file access history attribute in deciding which files are to be stored in the local hard drive and which should be migrated to network storage or archive.

Abstract: An improved file system for managing data storage and retrieval in a clustered UNIX computer system including a plurality of processing nodes and an interconnection network connecting the processing nodes. The improved file system includes a data storage device, such as a disk storage unit, connected via a shared SCSI interconnect with each one of the processing nodes, rather than connected directly with a single processing node. The structure layout for the file system, which is maintained on the data storage device, includes sufficient information to enable all of the processing nodes to access said file system.

Abstract: In an information retrieval system, a query issued by the user is analyzed by a query engine into query elements. After the query has been evaluated against the document collections, a resulting hit list is presented to the user, e.g., as a table. The presented hit list displays not only an overall rank of a document but also a contribution of each query element to the rank of the document. The user can reorder the hit list by prioritizing the contribution of individual query elements to override the overall rank and by assigning additional weight(s) to those contributions.

Abstract: A relational database management system (RDBMS) efficiently evaluates correlated subqueries by decorrelating them and taking care of the so-called SQL count bug and yet avoid using the expensive outer join operation. When there is no tuple match from a correlated subquery, the RDBMS query processor returns a tuple of null(s) from a scalar derived table, and then uses COALESCE function to generate a proper count value of zero from the null. The correlation level remains one. The query processor also performs a pass-through optimization to eliminate a join operation for floating SELECT operation by removing a join operation involving the magic operation, so that the correlation bindings are received from the correlation source table rather than the magic operation.

Abstract: An architecture for a single chip dynamic video random access memory using a single clock to operate the random port to perform refresh, memory address, and to control the internal circuitry for inputting data and addresses and for outputting data as well as modifying information in the memory circuit chip having internal circuitry for performing drawing or replacement rule logical operations on an addressed line of stored video information In the RAM and further having the write masking circuitry for modifying selected portions of the line of stored video Information between selected START and STOP bit locations within the like.