Abstract: A realtime engine for interfacing one or more data feeds with an applications. Each of the data feeds delivers realtime data for each member of an associated group of items available through the data feed. The interface includes logic for caching the most recent data values received from a selected one of the data feeds for at least some members of the associated group of items for the selected data feed. The interface also includes logic for sending at least some of the cached data values to the application in response to a request for updates.

Abstract: An application module of a data processing apparatus requires various quantities of memory space for the buffering of data to be processed. In particular, image and audio files are to be read from a CD-ROM disc and decoded in real-time. The operating system provides a memory manager to allocate buffer space from the available memory. To alleviate the problem of fragmentation, a fragmented memory manager module secures at the outset an allocation of buffer space sufficient for all requirements of the application module, and partitions the allocation into small units of buffer space (fragments), which are linked into a list by respective list pointers. Any subsequent requirement for buffer space is met by the fragmented memory manager, by un-linking the requisite number of fragments from the list of unallocated fragments. The application module is adapted to use fragmented buffer space where possible, while the allocation of buffer space in contiguous blocks is not excluded when necessary.

Abstract: A method and apparatus for determining whether a record, or an edited version thereof, is stored in a computer system. With this invention, whenever a record is stored in the system a hash function is applied to subsets of a key representing the record to be stored to generate multiple hash addresses. A copy of the key, or pointer thereto, is stored at each of the generated hash addresses. Whenever one wishes to determine whether a key is stored in the system, a hash function is applied to subsets of the test record to generate multiple hash addresses. The key for the test record then compared with the key stored in each of the generated hash addresses. If the key for the test record is sufficiently close to anyone of the keys found at the hash addresses, the test record is assumed to be stored in the system.

Abstract: In a disk file control device in which updating data output by a data processing section is temporarily stored in a FIFO queue to update a file, the updating data has a data structure which includes an operation code representing a type of updating operation such as a data inserting, removing or updating operation, and amount-of-data information indicating an amount of data to be subjected to the type of updating operation. The type of operation is determined from a given operation code and is used to change the size of file to be updated by as much as an amount of data obtained from the amount-of-data information, and thereafter the data stored in the FIFO queue is transferred into the file thus changed. Alternatively, the type of operation is used to change the size of the original file to be updated to provide a new file, and the data of the original file and the FIFO queue are transferred into the new file.

Abstract: In a data processing system having on-line storage containing data entities to be sorted and a central processor unit, a sorting machine interconnected with both. The sorting machine functions independently of the central processor unit except for the use of a start and finish signal. The sorting machine contains all logic elements required for sorting and merging thus rendering it independent of the central processor unit. The sorting machine includes two control buffers holding data representing parameters selected for the data processing operation, a job identification control buffer, and a plurality of cells each of which contains two key buffers holding data used for a sort/merge basis, two pointer buffers holding data defining an original sequence order for key data, a control register for indicating the last data to be sorted, and a processor for logically comparing pairs of data entities being sorted and for determining further cell directions.

Abstract: A data file arranged in one-to-one correspondence with one unit, and a connection definition table, arranged in correspondence with each unit, for defining a data file of an arbitrary unit to which data is to be transmitted, are arranged. The unit processes data in its own data file, and writes the processed data in a data file defined by the connection definition table.

Abstract: An electronic filing apparatus is provided in which a logical page number of an image data item is read out from a specified area when the image data item is input and the logical page number is set to correspond to a physical page number determined by the actual input order of the image data items. When the image data is retrieved, the image data items are displayed in the order of the logical page numbers. The registering operation will not be interrupted even when the order of the logical pages is wrong at the input time. Therefore, the registering operation can be continuously effected irrespective of the input order of the image data items and time and labor for interrupting the registering operation when the page order is detected to be wrong at the time of input of the image data items or inputting the image data items again can be reduced.

Abstract: A random sample is obtained from an inverted tree data structure by maintaining a cardinality estimate for each intermediate node in the tree, and selecting a leaf node at random by descending from the root node and performing an acceptance/rejection selection at each intermediate node weighted proportional to the cardinality estimates of the children and weighted inversely proportional to the cardinality estimate of the intermediate node. Even though the selection of an intermediate node is based upon only an estimate of the true cardinality of the intermediate node, the error in the estimate does not cause bias in the overall sampling method because any bias in the selection of the intermediate node is cancelled by an opposite bias in the selection of the child of the intermediate node.

Abstract: In a file update processing apparatus incorporating files, a list having a matrix arrangement is automatically formed. In this list, files names are listed in one column in correspondence with the respective files, and directory names are listed in the other column in correspondence with directories. In addition, identification data indicating the correspondence between the directory names and the file names are included in the list, thereby clearly indicating specific files defined as update targets in units of directories. In addition, lists, each having a matrix arrangement, are automatically formed in units of arbitrarily designated files. In each list, field names of records constituting the designated file are listed in one column, and directory names including file update definitions for defining the designated file as an update target are listed in the other column.

Abstract: A computer system, having external peripherals, includes an operating system and application packages residing therein. Data exchange logic permits an outside application package (generated by a third party to perform a predefined application function in a general purpose computer environment) to be integrated into the computer system. A data file containing information for making the necessary data available to the outside application package in the computer system is generated off-line. When the outside application package is executing in the computer system and it is desired to obtain the necessary data, a first package is accessed. The first package utilizes information contained in the data file to generate commands to obtain the necessary data. Information of the data file includes source information of the necessary data internal to or external to the computer system. If, however it is desired to output results of the predefined application function, a second package is accessed.

Abstract: During the processing of a transaction or other distributed computation, a computation management system creates a number of agents to handle various aspects or portions of the computations to be performed. Each agent progresses through a predefined set of state transitions which define the status of the agent at any point in time. The computation management system defines for each agent a set of dependencies, each dependency corresponding to a state transition which will be blocked until a particular state transition occurs in another specified agent. By defining selected combinations of dependencies for each agent, a variety of different interdependencies and cooperating protocols can be implemented. The distributed processing management system can be used both for managing transaction processing and for synchronizing events in other types of distributed computations.

Abstract: The multiple step data read apparatus provides a buffer memory (108-0) for each read/write head (110-0) in the rotating media (111-0) data storage system that can store up to the entire track (400) of data that includes the requested data (Sectors 2-6). The data is fragmented such that the data transferred into the read/write head buffer first is transmitted to the control unit first whether or not that data is at the beginning of the data requested by the control unit. The data is further fragmented such that critical portions of the data are available to the control unit to satisfy the host request as soon as the data is read from the device. This fragmenting results in the data becoming available to the control unit in the minimum time possible and the performance of the subsystem being the maximum possible.

Abstract: A microcomputer system employing an 80386 CPU and an 82385 cache controller has the capability of functioning with dynamic bus sizing (where the CPU interacts with devices which may or may not be 32-bits wide), as well as posted write capability. Unfortunately, the two capabilities have the possibility of an incompatibility if a write cycle is posted to a device which cannot transfer 32 bits on a single cycle. The present invention provides logic to overcome this incompatibility. An address decoder is provided to decode the tag portion of an address asserted on a CPU local bus to determine if the asserted address is inside or outside a range of addresses which define cacheable devices. Any cacheable device is by definition 32 bits wide and therefore posted writes are allowed only to cacheable devices. Accordingly, the microcomputer system employing the invention posts write cycles to cacheable devices; write cycles to non-cacheable devices are inhibited from being posted.

Abstract: A menu-driven system for developing Man-Machine Interfaces (MMI) for use in the graphical monitoring of ladder logic programs executing in programmable logic controllers PLCs. The Man-Machine Interfaces graphically depict plant processes controlled by the PLC. Data from the PLC representing plant process events (flows, state changes, tank levels, etc.) are communicated to the Man-Machine Interfaces. A Development System provides a programmer's "tool box" for constructing the Man-Machine Interfaces. Ladder logic programs and databases associated therewith are imported and accessed by the Development System for use in the development of the Man-Machine Interfaces. A Runtime System provides an execution environment for the Man-Machine Interfaces. The Runtime System has the ability to access ladder logic programs during monitoring operations. A user can "hot-key" to the ladder logic program for trouble-shooting purposes.

Abstract: A method for storage and retrieval of both time-oriented versions and view-oriented versions of engineering change information in which the engineering change information progresses through a set of status conditions and access to the data by different user groups is conditioned upon the status of the information. Version control software logic enables users to create versioned objects by logical key grouping of data elements. The version control logic acts upon the logical keys and special versioned attributes of these objects for the proper specification and selection of object instances during creation, update or retrieval processing. Insert and extract sequence numbers are automatically generated for both historical preservation of previous engineering change information and efficient retrieval of the currently effective designs.

Abstract: A virtual computer system having a translation lookaside buffer which converts a virtual address to a real address comprises a register (VMNR) for storing the identification number (VMID) of a currently running virtual machine, the translation lookaside buffer having a bit for holding the VMID and a comparison circuit which compares the VMID held in the bit with the VMID provided by the VMNR and predicates the success of conversion from a virtual address to a real address on the basis of a matching result of comparison, a management table for holding data indicative of VMIDs used to define virtual machines which have run up to the current time point, and a control circuit which, when an invalidation command for the translation lookaside buffer is issued during a run of a virtual machine, selects an unused VMID as first information for defining the running virtual machine on the basis of the contents of the management table and sets the selected VMID in the VMNR.

Abstract: A compiler apparatus in a computer converts source program to object program to be executed by the computer. If loop instructions are included in the object program, the resource reference extraction section extracts resources referred by the loop instructions and the resource change extraction section extracts resources changed by the loop instructions. The loop parallel decision section decides possibility of parallel execution for different stages of the loop instructions according to the extraction result.

Abstract: A relational data base system useful for managing a data communications network from a central repository employs a nonstandard reference key along with primary and foreign keys to research, address, retrieve and manipulate records of functional and physical entities and attributes of nodes and links that form the network.

Abstract: A system for the automatic adjustment of resources devoted to query optimization according to estimated query execution time. The disclosed system permits the query optimizer to automatically trade off the time spent estimating the execution cost of alternate query execution plans against the potential savings in execution time that one of those alternate plans may yield. The number of alternate plans considered is adjusted by selecting compile-time parameters and heuristic criteria for limiting the primitive database operators used in the alternate plans, thereby establishing a new search space. The parameters and criteria are adjusted according to the estimate of execution cost for the optimal plan from a first search space. The first search space may be relatively small and quickly evaluated. Evaluation of larger subsequent search spaces is optional according to an automatic thresholding process of the disclosed system.

Abstract: An apparatus for manipulating a relational data base includes a unit for describing input data in a table format, a unit for describing all the operational manipulation with respect to the input data in a non-text format, and a unit for outputting data by referring to the relational data base based on the described input data and operational manipulation. The input data of a table format includes an input table and an output table. The input table includes an operational description region and the output table includes a region wherein a map relation between the respective items of the input and output table is described. The manipulation contents are described in the operation manipulation description region and the map relation description region. The operation flow is described and defined by a connection line with directiveness.