Abstract: Techniques for improving overall data throughput in a computer system, especially during the playing of movies from CD-ROMs provides for a direct flow of data between the CD-ROM and the MPEG card, greatly reducing system memory usage and bus utilization. Control circuitry is responsive to signals from the CPU, which signals specify whether data from the CD-ROM can be sent directly to the MPEG decoder circuit or needs to be sent over the buses to the system memory. Accordingly, different transmission paths are used, depending on the attribute and destination of the data in order to reduce unnecessary data flow in the system and unnecessary consumption of system resources.

Abstract: Compilation and virtual machine arrangement and process for translating source code including pre-runtime executable instruction into compiled code having enhanced runtime effectiveness. The source code is formatted in accordance with a user determined and pre-runtime modifiable language definition. The source code is compiled by a generalized compiler and includes executable language specific structure constructs or instructions which pass through the generalized compiler in unexecuted form. The instructions are then executed in a virtual machine which produces compiled code of reduced size, which renders runtime execution of the compiled code of increased effectiveness.

Abstract: An electronic spreadsheet system of the present invention includes a notebook interface having a plurality of notebook pages, each of which may contain a spread of information cells, or other desired page type (e.g., Graphs page). Methods are provided for rapidly accessing and processing information on the different pages, including displaying a plurality of page identifiers for selecting individual pages, and further including a preferred syntax for referencing information. Additional methods are provided for editing cells and blocks of cells.

Abstract: A user interface technique for applying attributes to screen objects. The user selects a screen object, and causes the display of a dialog box for changing an attribute of the screen object. The dialog box includes an attribute palette or other controls used for setting attributes, as known in the art, but also includes a sample box in which a replica of the selected screen object (or a portion thereof) is displayed. The user then takes the actions necessary to select the desired attribute, in response to which the replica in the sample box is updated with the desired attribute. Once the user is satisfied with this previewed result, the user can accept the changes by clicking in the "OK" button or reject the changes by clicking in the "Cancel" button.

Abstract: A system for creation and completion of goal oriented electronic forms creates a graphical image data file which defines: a graphical image of a form for display and printing; a graphical image of tree branches, tree nodes, and conclusions in association with fields of the form; reading and writing links between form fields and data sources and destinations; and links to other forms which, with the original form, comprise a related stack of forms. The system includes a form creation mode and a run time mode. The trees are defined by an application developer using the form creation mode to establish both qualitative and quantitative relationships between the various fields on the forms thereby providing the basis for the goal oriented prompting for the application user using the run time mode.

Abstract: A Client/Server Database System with improved methods for appending items to an object, such as appending data records to a database table, in the context of a multi-user environment is described. The system includes one or more Clients (e.g., Terminals or PCs) connected via a Network to a Server. The Clients store data in and retrieve data from one or more database tables resident on the Server by submitting SQL commands, some of which specify insert or append operations, for appending records to a table. For enhancing the speed in which multiple appenders (i.e., Clients) can append records, the operation of the server is modified to store an object (e.g., table) as multiple (physical) page chains. From the logical viewpoint, a single (logical) page chain of data pages is presented to each client or user. From the perspective of inserting records, however, the system has multiple page chains to insert into, thereby removing contention among multiple appenders for the last page.

Abstract: Non-modal database system having methods for incremental maintenance of live views is desribed. The database system maintains a single-context workspace throughout an entire user session; here, the user creates a base document (database) for storing user-supplied information. In a typical session, the user takes "views" of the base document, for presenting the information according to a user-selected format and according to user-specified criteria (if desired). More particularly, the system maintains "live" views of the data so that all views of a particular base document (or documents) reflects at all times the state of the underlying data. By employing "incremental queries," the system of the present invention can at all times maintain the "liveness" of user-designed forms and reports, all without having to re-execute queries or re-paginate reports.

Abstract: A development system having a compiler, a linker, and an interface is described. The compiler, which generates or "compiles" source listings into object modules, includes a parser for parsing information. Parsed information, which is initially stored in a parse tree, is further processed. A hash table is initialized for storing a unique address or signature for a particular data object (or set) of the tree. The nodes of the parse tree are processed in a "preorder" traversal. If a node under examination is not stored in the hash table, it is installed in the table and its address (hash address) is returned for storage in the tree. Other nodes of the tree are (recursively) processed in a similar manner. Two identical trees encountered in a parse will hash to the same address and thus need only be stored once. If two trees differ by only a small amount, only the difference and the left edge of the second tree will be stored in addition to the first.

Abstract: A data access system of the present invention includes an interface (client), a data engine having a common application programming interface layer, and data drivers. Through the drivers, the data engine (responding to client requests) accesses foreign data objects, which may include information tables, files, and other data objects of a foreign format. In this manner, the system provides a virtual interface between a client (e.g., database manager) and individual foreign data objects (e.g., database files). Regardless of the format of the individual database files, all files can be shared without the need to make copies.

Abstract: A data backup system implements coordination between a Database Server and a Backup Server to produce a recoverable database dump. By utilizing a technique referred to as stripe affinity, a mechanism is disclosed for ensuring the integrity of a database backup made to multiple archive devices simultaneously. In addition, by utilizing stripe affinity, archived data may be reloaded from fewer archive devices than were used to make the original backup.A task scheduler mechanism allocates processor time among the tasks that comprise the backup system. In this way the I/O service tasks can process their event queues while the current set of allocation pages are also being processed.

Abstract: Database system and methods are described for improving execution speed of database queries (e.g., for decision support) by optimizing execution of nested queries or "subqueries," such as are commonly used in client/server database environments. In particular, a subquery cache is provided having a size which can be dynamically adjusted by the system during execution of the query, for achieving an optimal cache size. During execution of the subquery, the system keeps statistics on cache "hits" and "misses." Specifically, the system stores a count of the number of times a row is found in the cache (i.e., a "hit") as well as a count of the number of times a scan of the cache yields no "hit" (i.e., a "miss"). Also, a maximum LRU (least-recently used) depth of the deepest hit in the cache is also tracked. This tracks how deep (i.e., the deepest row) into the cache there has been a "hit.

Abstract: System and methods are provided for optimizing the access of information, particularly in response to ad hoc queries or filters. The system of the present invention includes a computer having a memory and a processor, a database for storing information in the memory as field values in a record, an indexing component for referencing a plurality of records by key values of the field(s), an input device for selecting desired records by entering a filter (query) condition corresponding to values stored in the field(s), and an optimization module for providing rapid access to the desired records. The optimization module employs one or more existing indices for optimizing data access, including using ones which do not directly support the filter expression. In instances where no indices are available, the optimization module may employ a "learned" optimization method of the invention for on-the-fly learning of records which meet the filter condition.

Abstract: An electronic spreadsheet system includes a notebook interface having a plurality of notebook pages, each of which may contain a spread of information cells, or other desired page type (e.g., Graphs page). Methods are provided for rapidly accessing and processing information on the different pages, including displaying a plurality of page identifiers for selecting individual pages, and further including a preferred syntax for referencing information. Additional methods are provided for editing cells and blocks of cells.

Abstract: A server performs an indexing method of data management to create and maintain indexes more efficiently than existing indexing approaches. The server is disposed between an application program and a DBMS and is coupled to a data base located within the DBMS. The data base has an ordered set of data values stored in memory. Each data value has a bit pattern and an identifier associated therewith. The server creates a plurality of bit vectors such that the number of bit vectors created equals the longest length bit pattern for the values. The server accesses one of the values stored in the data base. Each bit of the bit pattern for the value is then assigned by the server to a unique position in successive bit vectors. The bits are assigned to identical unique positions in each of the successive bit vectors. The server repeats the above-described accessing and assigning steps for each remaining value of the set to form an index of bit vectors for the values.

Abstract: Database system and methods are described for maintenance of B-Tree indexes, such as are commonly used in a relational database environment. "Load patterns" are monitored, for optimizing B-Tree node splitting, based on a particular load pattern's effect on B-Tree growth. More particularly, an "ascending insert" load pattern--that is, the insertion of data records for a multi-column table where the particular records to be inserted have a fixed value for the first column and a monotonically increasing value for the subsequent column(s)--can be identified and optimized. Methods are described for splitting the B-Tree nodes or pages, not at the half-way point, but instead exactly at the point of insertion, a position where the insert row would have gone into the page (had it not overflowed).

Abstract: An electronic spreadsheet system of the present invention includes a Formula Evaluator having a preferred interface and methods for compiling spreadsheet formulas into native machine language for a target processor/coprocessor. Methods are provided for improved cell lookups, whereby a system memory address for a cell record may be compiled directly into the machine language sequence for a compiled formula. Additional methods are provided for simplifying error checking. The methods adapt NaN (IEEE format) values for encoding spreadsheet ERR and NA values, so that the on-chip logic of the coprocessor may be employed for correctly propagating ERR and NA values. Preferred auditing methodology is also described, which includes further modifying the format of NaN values so that a NaN encoding an ERR or NA also embeds the address of the originating cell (i.e., the first cell which first gave rise to the ERR or NA value).

Abstract: Method and arrangement for dynamic, run-time alteration of pre-set variable space relationships by run-time GUI modification of object connections associated with the variable spaces. Arbitrary linkages between all variable spaces are established prior to runtime to allow initial conditions for variable resolution irrespective of anticipated or actual object connections. Thus all variables associated with objects are prespecified and provided with initial values, so long as a value has been assigned to the variable in some object. When actual object relationships are indicated at run-time, these effect new variable space linkages. The initial and subsequent linkages are effected with pointer addresses within the respective variable spaces.

Abstract: An electronic spreadsheet system includes a notebook interface having a plurality of notebook pages, each of which may contain a spread of information cells, or other desired page type (e.g., Graphs page). The system includes a spreadsheet application development module having a user interface (UI) builder. The UI builder provides "live" links between system objects. In particular, link commands are provided as statements a developer may attach to a control to indicate what should happen when an end-user activates or changes the control. Link commands usually specify three things: an event, an action, and an object. The event indicates what occurrence should trigger the link command; the action indicates what should happen. The object is what should be acted upon. One control can have many link commands. In operation, a link command can send a value to a cell in the notebook, run a macro, close a dialog box, change the zoom factor in the notebook, or the like.

Abstract: An electronic spreadsheet system of the present invention includes a Data Modeling module for creating multi-dimensional reports from spreads of information. The module includes a preferred report workspace interface--a Data Modeling Desktop--for receiving a user-specified range of source data from an electronic spreadsheet, which may include 2-D as well as 3-D ranges of source data from a spreadsheet notebook. In response to user inputs, the system assembles a corresponding multi-dimensional report by transforming 2-D or 3-D spreadsheet information into multi-dimensional format. In this manner, users can continue to build spreadsheet models on an ad hoc basis (i.e., without designing complex multi-dimensional data models beforehand).

Abstract: A system of the present invention includes a relational database management system (RDBMS) having a hypertext report writing module. Methods are described for automatically recognizing relations between reports which are generated from the same or related database tables. The system automatically embeds (or assists the user in embedding) appropriate hypertext links so that information from one report may be cross-referenced immediately with information in another, related report. Drill-down hypertext reports of increasing level of detail are illustrated. In addition to drill-down reports, the system may create comprehensive hypertext reports for automatically tying together information which is related through underlying table relations but which ordinarily appears in different reports. By automatically placing hypertext links or cross-indexes between reports, the system ties together relatable information into a single, cross-indexed hypertext report.