Showing papers on "Data access published in 1989"

A file system for a plurality of storage classes

Abstract: A file system for managing data files for access by a plurality of users of a data processing system that includes internal storage (41) for buffering, external storage (44), and a file user interface (I) by which the plurality of users request access to data files. A first level, coupled to the file user interface (41) for temporary storage of data to be accessed by the plurality of users, and generates requests for transactions with external storage (44) in support of such allocations. A second level is coupled to the first level and the external storage (44) and responds to the request for transactions with the external storage (44) for managing the transactions for storage of data to, and retrieval of data from, the external storage (44).

A technique for summarizing data access and its use in parallelism enhancing transformations

Abstract: Most existing systems for automatic detection of parallelism concentrate on finding “loop parallelism”, in which the separate iterations of a loop are executed in parallel [2, 7, 111. H owever, there are many programs in which performance improvements can be achieved by also seeking “task parallelism”, such as parallelism between different loop nests or subroutine invocations. In this paper we are concerned with automatically uncovering task parallelism and supporting manual insertion of task parallelism. Although the data dependence graph of a program has proven useful for the detection of loop parallelism, it is not ideal for detecting task parallelism, primarily because the number of data dependences is very large even for programs of moderate size. Uncovering and enhancing task parallelism using the dependence graph can require the examination of every dependence edge between each pair of regions that are candidates for task parallelism an expensive procedure. It would be much more efficient to summarize the effect of all the data dependences between tasks, and use this summary to guide the parallelism detection procedure. In this paper, we present a technique for summarizing the data accesses in a given region and show how this summary can be used to detect and enhance task parallelism in a program. For the sake of simplicity, we restrict our discussion to Fortran programs that consist of a sequence of perfectly-nested loops in which all subroutine calls are expanded inline. However, the

System for accessing remote heterogeneous database including formatting retrieved data into applications program format

Abstract: An improved method for access to data from a remote computer and an improved method for accessing remote heterogeneous data bases. The method includes a personal computer having an application program for processing data by keyboard input that operates on a local applications data base having files with a first file structure. A remote host computer accesses data in remote files having a second file structure. A preselected keystroke of the first computer modifies the data accession program of the remote computer to reformat retrieved data in the format of the personal computer applications program before transmission back to the personal computer, so that the personal computer resident portions of the program require no information as to where the requested data is located or what the host computer file structure is.

Shared memory multiprocessor system and method of operation thereof

Abstract: A digital data processing apparatus has plural processing cells, each with a memory element that stores data page made up of plural subpages. At least one of the cells includes a CPU that can request access to a data subpage. A memory manager responds to selected data access requests by (i) allocating, within the memory local to the requesting CPU, exclusive physical storage space for a data page associated with the requested subpage, and (ii) storing the requested subpage in that allocated space. The apparatus recombines data pages and deallocates them on the basis of usage and access state. The apparatus also accesses data asynchronously with respect to execution of instructions by the CPU.

Data carrier-controlled terminal in a data exchange system

Abstract: A terminal (10) in a data exchange system with exchangeable portable user data carriers (4) has for their connection at least one connecting unit (3) and has further at least one data input unit (5). Exchangeable control modules (8, 9) are connected through one or more other, preferably similar, connecting units (6, 7). The modules are equipped with microprocessors and contain mechanically and cryptographically protected memory areas which receive secret data and keys for the secure carrying out of identity and authenticity tests, as well as application specific operational programs. These construction methods offer high security against unauthorized data access as well as against fraudulent manipulation of the device. They also greatly simplify the application independent design and construction of the terminal.

Integration of buffer management and query optimization in relational database environment

Abstract: In today’s relational database systems, query optimi7alion and hufTer management are generally treated indrpcndently. I Iowever, the query access plan con(ains information on data access patterns which can he useful hints to the huffcr matIager. T;urlhermore, the optimal access plans under dilTerent huffcr sizes can be quite difTcrent. In this paper, an integrated approach to buffer management and query optimization is proposed and analyzed. ‘I he query strategy of all transaction types is simultaneously considered together willt the hulTcr allocalion strategy so as to optimbe overall system performance. As the buffer allocation depends upon (he hulTer holding time or transaction response time whicft iz dcfrrn~ir~rd h) the buffer allocation and query optimization slrnlcgirs, ;III oplimization method combining a integer programming model with a queueing model applied iteratively is developed lo capture this effect. To reduce the size of the optimi7atinn problem, a methodology hascd on the concept of hulrcr consumplion is proposed to pre-analyze the query and suhstacltially cut down the access plans to be considered. A detailed simulation is used to demonstrate fhe superiority of ihe intcgrated strategy as compared to other hulTcr tnannpenrrnt strategies based on working set and hot set.

Negotiating data access in federated database systems

Abstract: A protocol is presented for negotiating access to data in a federated database. This protocol deals with several important aspects of data sharing in an environment where databases belonging to different organizations coexist and cooperate. It is based on the concept of quasicopies. These are cached values that are allowed to deviate from the central value in a controlled fashion. The degree of consistency of a quasicopy is established by the entity where the quasicopy is to reside. Two techniques are presented that can be used for numerical data and for copies that rely on version numbers. It is believed that these two ideas encompass many of the interesting cases in practice. However, it is also possible to fine tune the estimation of this function once the exact semantics of the data involved are known. >

Dynamic page migration in multiprocessors with distributed global memory

Abstract: A mechanism called the pivot mechanism is introduced and described. It controls the dynamic migration of data pages between neighboring memory modules during program execution to improve the performance and programmability of multiprocessors with distributed global memory. The programmer or compiler is relieved from the data allocation task; moreover, because data allocation is dynamically modified to minimize communication traffic, algorithms with varying and unpredictable data access patterns can run efficiently. Flexible data migration serves the dual purpose of making algorithms the efficient machine-specific and making possible the efficient execution of algorithms for which a good static allocation is not possible. Simulation results based on a mesh-connected multiprocessor performing a matrix multiplication are presented. >

QuickSilver support for access to data in large, geographically dispersed systems

Abstract: QuickSilver is a distributed operating system that is intended for large, geographically dispersed systems. The authors describe how clients and data servers interact in the QuickSilver system to access distributed data in the context of large, geographically dispersed systems in which there are many different kinds of data servers. An interface is defined that provides a uniform way for clients and servers to exchange information about each other and to access data objects. The interface attempts to minimize the number of messages needed for this. It supports efficient interaction with higher-level client and server semantics by appropriate use of high-level abstractions and operations, and by selectively exposing the parameters governing communication connections to higher layers of the software. >

An Image Handling System For Medical Image Processing

Abstract: The processing of medical images requires the handling of complex structured sets of elementary objects (images, curves,... and their associated parameters). Usually, an elementary object cannot be interpreted without information concerning the structure to which it belongs (e.g image sequences). Then it is necessary to consider the whole structure like an atomic semantic entity, object of an image data base. As specific tools are necessary to manage these objects, an object oriented handling system (OHS), part of our medical image data base project (BDIM), was developed to perform : i) the array storage management, ii) the interface between applications and the BDIM to have access to objects (create, update, delete...) and components (navigation inside object structures, access to arrays and parameters). The image handling system (IHS) decribed here is the user level part of the OHS. IHS allows the evolution of the data base environment by adding or updating acquisition and/or processing functionalities. To unify data access methods, the concept of logical file is introduced as a special class of BDIM objects. The logical file does not necessitate the use of a specific declaration for the different kinds of images because it is possible, for a desired processing , to have access to the only concerned data.

Content-addressable mass memories

Abstract: In the area of non-numerical data processing, the usual local addressing with its fixed access path is troublesome and time-consuming if very large data sets have to be handled. Next to the well-known software procedures more and more hardware solutions are sought for supporting the typically content-addressable data access. The apparently ideal solution of a parallel associative memory cannot be implemented in the capacities of mass memories, but it can be substituted for mass memories with content addressability.

Cache memory control system for parallel computers

Abstract: PURPOSE:To reduce the overhead for inter-processor communication and data relaying, by transferring data to a cell of the access request source if desired data exists in the cache memory on a cell which the data access request passes. CONSTITUTION:Each cell 2-1 is provided with a cache memory 5-i in which data which at least this cell itself requires or data transferred through this cell on demand is held; and if desired data exists on a cache memory 5-k of a cell 2-k which the data access request from a certain cell passes, this data is transferred to the cell which issues the data access request. Thus, the overhead for inter-processor communication in case of data access to another cell or the overhead for data relaying is reduced.

High speed relational data base processor

Abstract: The present invention is a data base information engine subsystem which examines data on the fly as it is retrieved from a mass storage device (i.e., disk), and before storing it in memory, to select only the specified elements of data required by the host computer according to criteria set forth by the host computer. A page mapper circuit separates the host command processing from the data access processing for the command. The instruction set used by the information engine subsystem contains optimizing algorithms to parse and reorder the required operation to be most efficient (with respect to time). The information engine subsystem also contains a high speed processor which is a special purpose processor designed and optimized for data retrieval while doing operations on the data at high speed.

Address conversion system

Abstract: PURPOSE:To develop an information processing system superior in productivity and high in reliability by detecting access to data by a logic pointer, and converting a code to an instruction code to make access to the data by converting logic address to a physical address by a compiler CONSTITUTION:The compiler recognizes a specific variable as a pointer variable in which the logic address is attached, and generates an object code to call an address conversion mechanism 3 according to a decided connecting specification for the reference of the data indicated by the logic address And the object code to make access to the data is generated by the physical address 4 that is a conversion result Normally, a value in which one time of conversion is applied can be used as it is for a short period Therefore, the compiler can manage the effective period of a converted physical address by a context in a program targeted to be compiled In such a way, it is possible to eliminate a redundant address conversion code and to improve the execution efficiency of the program

IMS Administration, Programming, and Data Base Design

Abstract: Part 1 Goals and uses of the data base design: representing the data program access efficiency. Part 2 Logical design: data models and transaction analysis entity/relationships normalization IMS logical design IMS data access considerations secondary indexes logical relationships. Part 3 Pysical design: VSAM versus IMS segments access methods data set groups compression pointers example logical relationships data sharing - why IMS restricts sharing DBRC setting up a data sharing environment DBRC commands setting up jobs to run with data sharing. Part 4 Data base support: program support - PSBs testing support production support. Part 5 Utilities and tuning: recovery utilities reorganization utilities other utilities supplied with IMS other utilities buffers DB monitor DOS DL/I utilities. Part 6 On-line considerations for the DBA: the DBA's role in the online environment recovery DMB and PSB pools making online data base available for b

Super-large capacity data storage drive

Abstract: A fast access high capacity data storage system includes a disk-based storage system employing a plurality of storage surfaces (2). Selected storage surfaces of the plurality thereof include a plurality of data access heads (4) in data communication therewith. Means (6) is provided for allowing concurrent data transfers through this plurality of data ac­cess heads (4). Performance is further improved by monitoring frequently accessed data records and transferring them to re­cording surfaces less frequently in use. Means (48, 49) is al­so taught for moving the data access heads (4) of the plurali­ty to other recording surfaces (2) to decrease access bottle-­necks thereon.

Verfahren zur adressbereichsueberwachung bei datenverarbeitungsgeraeten in echtzeit

Abstract: The memory regions 17 of a computer are monitored by a programmable hardware circuit including a RAM 3 which stores permissible accesses associated with different access levels; and the circuit permits memory access only to predetermined regions. If there is an unauthorized access attempt to a memory cell, the program location in the memory initiating the unauthorized access is detected at 14, the respective program is stopped and an alarm 402 is actuated. In this way, procedures for protecting the operating system cannot be circumvented to gain unauthorized access to data. After programming of the RAM 3 is completed, write-in access to it is terminated by a flip-flop 12 and cannot be renewed except by actuation of a switch 13. Removal of the circuit will cause short circuits, thus making it impossible to shut the circuit off without being detected.

Data access system

Abstract: PURPOSE:To eliminate the undesired transfer of data carried out for each file and to omit the production of a new display program by realizing accesses from a man-machine device for each element data of a data file by means of a template set at a processor. CONSTITUTION:When an operator selects screens via a man-machine device 1, a screen display controller 12 selects the fixed screen data out of a screen data file 11 for display of a fixed screen. Based on this fixed screen, the operator designates a data address for the variable part of the fixed screen. Thus the controller 12 sends the corresponding data address of the variable picture data to a processor 2 out of the file 11. A selecting device 23 selects the corresponding data template out of a data template file 21 based on said data address for acquisition of the element data forming the files of a data file 22 designated by said data template and data address.

System for displaying memory capacity

Abstract: PURPOSE:To eliminate the uneasiness of an operator, by informing the storing state of data in an external data memory before starting the access processing of the external data memory. CONSTITUTION:The data storage capacity ratio of the external data memory 6 is displayed before starting a data access processing by operating a capacity calculation part 7 based on the operation of an access mode setting key. In other words, since the capacity calculation part 7 which calculates the data storage capacity ratio of the external data memory 6 is operated based on the access mode setting key operated before actual data access, the storing state of the data in the external data memory 6 can be confirmed in advance. In such a way, since the operator can predict the storing state of the data in the external data memory 6 easily in which the data is stored or it is erased, it is possible to eliminate the uneasiness of the operator.

Document filing system

Abstract: PURPOSE:To facilitate an access to data to be repeatedly utilized by totaling the frequency of accesses to respective data by a user in a prescribed period, selecting the data in which the access frequency is large, recording them to a table, thereafter, referring to the table, and executing the access to the data. CONSTITUTION:Each time the user executes the access to a node, a frequency table 16 is referred to, the total access frequency of said node until such a time is updated, and the total access frequency is totaled in the prescribed period. Next, the node in the frequency table 16 is sorted by the total access frequency, a threshold is provided to the number of nodes or the total access frequency, the node is selected in the order of the degree of the total access frequency, and such node information is written to a node table 13. When the user requests only the data (data to be always used), in which the access frequency is large, in the access thereafter, a node table 18 is referred to, and the node recorded is blousing-displayed. Thus, the blousing and access of the node to be repeatedly utilized can be easily executed.

Trade-offs Between Replication and Availability in Distributed Databases

Abstract: Distributed databases are generally built on top of standard communication facilities such as leased phone lines. Often several applications, running in different databases, use the same network for their communication. But the applications that run in these databases have grown increasingly more complex and demanding in their availability requirements, often with temporal constraints (such as real-time databases). We argue in this paper that there is a need for dedicated communication networks designed for specific applications. To design such networks, we argue that it is necessary to analyze the data access patterns in the applications that run on the top of the networks. Such analysis would give a network designer an insight into where and how much to replicate the data in the system. Replication can increase availability of data, but too much replication can also hamper it. Thus, for a given application, there exists a right balance between replication and availability. Our goal is to find this balance and show how to design a network of the cheapest cost that achieves it. In this paper, we take the first step towards the design problem by precisely characterizing the trade-offs between replication and availability and suggest a network design strategy to exploit these trade-offs.

Card data processing method

Abstract: PURPOSE: To intend the diversification of the contents of data processing using an IC card by storing the data to be used for the data processing in the plural detachable data storage areas of the IC card. CONSTITUTION: The data storage area to store the data necessary for the data processing is attached to the IC card 1, and an item and a condition necessary for the data processing and an executable instruction are inputted from an input device 141. A CPU 11 takes in the data structure of the corresponding data from an area 121 to control part 111 of the CPU 11 by the function of a load program 114. Next, a data access program 112 executes the designated data processing by using successively the data of the area 121 according to the referred result of the data structure by the control part 111. Thus, whatever data structure the data stored in the area 121 attached to the card 1 is, the data processing using above data can be executed. COPYRIGHT: (C)1990,JPO&Japio

Memory access controller

Abstract: PURPOSE:To improve the overall processing efficiency of a system by keeping the processing balance for memory access requests among processors. CONSTITUTION:A detection signal value '1' showing the inter-element distance is equal to a multiple of 0 or 8 is supplied from a corresponding distance detecting circuit 7 or 8 via a data line 107 or 108 while the equidistant allocation data access request of one of two processors is processed. Under such conditions, the access request processing start signal of the other processor is transmitted via a data line 201 or 202 after discontinuing the processing under execution in case the access request received from the other processor is equal to a single data access request or the equidistant allocation data access request other than those having the inter-element distance equal to a multiple of 0 or 8. When the processing of the other processor is through after said discontinuation, a process end signal is supplied via a data line 250 or 252 and the process restart signal of the discontinued processor is transmitted via the line 201 or 202 after reception of the process end signal.

Global information system issues

Abstract: A global information system (GIS) is an umbrella system that presents a global schema of the data available in its underlying, component, autonomous information systems and provides its users with the capability to ask queries of the global scheme and to receive integrated answers. The major research areas confronting GIS developers are examined. They are: development of global schema; query processing and data access; security; recovery from failure; integration of the user workstation with the GIS; and support for multimedia objects. >

Multi-user's system

Abstract: PURPOSE: To obtain a multi-user system with high flexibility by placing a limit to an access to a locked data object by other application support processors than a selected application support processor. CONSTITUTION: In a hierarchical data base, a locking means 52 locks a prescribed node in the common use access mode in response to a specific request to a data access system by a selected application support processor 14. The selected application support processor 14 has a read access right to the node and its all descendant nodes and other application support processors than the processor 14 cannot acquire an exclusive access right to the node and its all descendant nodes. Thus, the multi-user system with high flexibility is generated.

Data memory apparatus of control apparatus of papermaking machine

Abstract: PURPOSE: To flexibilize structure and efficiently carry out data access by interposing a data control part and making an access to a data storage part composed of a data accommodating part and the data control part so as to approach the data accommodating part. CONSTITUTION: A data accomodating part 60 has a multidimensional data structure of tables, blocks and records and a set of data is accommodated in one cell composing the data structure. A data control part 40 is provided with an address and a size of one cell of the data accomodating part 60. When the data are referred by other control parts, or the like, the data control part 40 is referred to know a rough address and then make an access to the data accommodating part 60.