Abstract: A method and apparatus allows adapting a standard flying prober system to manually or automatically determine the likelihood of error free probability of test point targets on Printed Circuit Assemblies (PCA's) which may have significant planarity irregularities. The method and apparatus provides a corrective function allowing error free probing of test target points on PCA's having planarity irregularities which otherwise make them impractical to test. The method and apparatus involves utilizing the camera system typically provided with a flying prober system and an auxiliary sighting system each having different optical axis angles, the use of which allows determination of height values.

Abstract: In an emulation of a multiprocessor Target computer system on a Host computer system, Host virtual memory addresses are mapped and utilized as Target virtual memory addresses. Target virtual memory control tables are setup accordingly. Each Target processor is mapped to a Host thread. When a page fault is detected by the Host operating system, it is checked to see if it belongs to the Target system, and if it does, the executing thread transfers its processor identity to a free thread, and then completes processing the page fault. Upon completion, it marks the processes that had been executing on that thread and processor as available for execution, then blocks until activated. Another thread, upon dispatching that process, wakes up the blocked thread and transfers its processor identity to that thread, which continues to execute the interrupted process.

Abstract: Atomic multiple word writes are provided when emulating a target system that supports atomic multiple word writes on a host system that does not. For each except the last word to be written, a gate flag is read, tested, and locked when it is found unlocked. The words are then written to memory in reverse order, unlocking the gate flags as they are written. In a host system with a longer word size than the target system, the gate flags can be stored in otherwise unused bits in the host system words containing the target system words to be written.

Abstract: A processor in a data processing system having multiple cache memories performs cache memory or processor module affinity dispatchin. Processes awaiting dispatch are stored in prioritized queues. Each queue has a priority chain, and a chain for each cache memory or processor module, with each chain containing processes ready for dispatch. The dispatcher checks the queues in priority order, starting with the priority chain for a queue, followed by the chain corresponding to the cache memory or processor module that the process last executed upon, followed by chains corresponding to other cache memories or processor modules.

Abstract: In an emulation of a multiprocessor Target computer system on a Host computer system, Host virtual memory addresses are mapped and utilized as Target virtual memory addresses. Target virtual memory control tables are setup accordingly. Virtual-to-real address translation of a Target system effective address to a Host system virtual addresses is performed by identifying a working space for the effective address, determining a working space base address for that working space, and then performing a linear translation multiplying the effective address by a constant and adding it to the working space base address to generate the host system virtual address.

Abstract: A method of addressing mass storage memory in which information is stored in Space Control Pages of physically contiguous disk segments subject to irregularities in the mapping is disclosed. Space Control Pages fall at regular intervals across the address space. An efficient hashing method is disclosed that first hashes record keys across the entire address space to form a hash index. If the hash index falls into one of the Space Control Pages, the key is rehashed across the contiguous hash space following the Space. Control Page utilizing a second hash function. The result of the second hash function is added to the start of the contiguous hash space following the Space Control Page to generate the hash index utilized for those records that initially hashed into a Space Control Page. In all cases the generated hash index is utilized to store and retrieve records in a database or hash file.

Abstract: A cache manager of a relational database management system (RDBMS) is able to bypass time consuming search operations through the use of a key memory structure and locate generated code segments within an SQL cache within a minimum of time. The SQL cache contains the generated code segments used to execute SQL statements as well as the structures and program logic used for maintaining the cache. The key memory structure is located in an area of memory utilized by the SQL runtime routines in executing applications. The runtime routines provide an interface between the application and the RDBMS.

Abstract: A system and method that enhances the data access performance of a multi-layer relational database manager by expanding the code generation component layer of the database manager to include a number of performance enhancing subroutines designed to execute functions performed by lower component layers substantially faster than if the functions were executed by such lower component layers. Each such subroutine includes logic for establishing the conditions under which the particular subroutine is invoked during the processing of a SQL request. During process of generating code for a specific SQL query, the code generation component layer inserts calls to the different performance enhancing subroutines in place of normally included calls to lower component layers. This results in the insertion of the different performance enhancing subroutines into the generated code.

Abstract: A client system utilizes a standard browser component and a transaction protocol gateway (TPG) component that operatively couples to the standard browser component. The browser component initiates the utilization of new session connections and reuse of existing session connections as a function of the coding of the universal resource locators (URLs) contained in each issued request. Each URL is passed to the TPG component that examines a context field included within the URL. If the context field has been set to a first value, the TPG component opens a new session connection to the server system and records the session connection information in a persistent session table (PST) component maintained by the TPG component. If the context field has been set to a second value, then the TPG component obtains the session connection information in the PST component for the established session connection and passes the data from the browser component to the server system over the existing persistent session connection.

Abstract: An Application Programming Interface (API) provides interoperability between different monitoring and administrative components of a data warehouse system that utilizes different standard protocols. One of the protocols is the well known data connectivity protocol, Open Database Connectivity (ODBC) that defines a standard interface between applications and data sources. A second one of the protocols is the well known network management protocol, Simple Network Management Protocol (SNMP) that defines a standard interface between an agent component and a network management system. The API provides a facility that enables the different components to access user and connection information maintained by an ODBC server component derived from servicing client system application SQL queries made by system users.

Abstract: A system and method that enhances the row retrieval performance of a multi-layer relational database manager by including in the code generation component layer of the database manager a row retrieval performance enhancing subroutine designed to execute functions performed by a lower component layer substantially faster than if the functions were executed by such lower component layer. The subroutine includes logic for establishing the conditions under which the particular subroutine is invoked during the execution of a SQL request. The output code generated to execute a specific SQL query, including calls to the row retrieval subroutine in place of normally included calls to the lower component layer. This enables the generated code to perform lower component layer functions with specialized code designed to increase performance based on the characteristics of the data being retrieved.

Abstract: A system and method that enhances the index processing performance of a multi-layer relational database manager by expanding the code generation component layer of the database manager to include an index processing performance enhancing subroutine designed to execute functions performed by lower component layers substantially faster than if the functions were executed by such lower component layers. The subroutine includes logic for establishing the conditions under which the particular subroutine is invoked during the execution of a SQL request. The output code generated to execute a specific SQL query, including calls to the index processing subroutine in place of normally included calls to the lower component layer. This enables the generated code to perform lower component layer functions with specialized code designed to increase performance.

Abstract: A client system utilizes a standard browser component and a transaction protocol gateway (TPG) component that operatively couples to the standard browser component. The browser component initiates the utilization of new session connections and reuse of existing session connections through the use of session pools as a function of the coding of the universal resource locators (URLs) contained in each issued request. The gateway component builds a plurality of session pool table structures at client system startup that define an initial number of pre-established persistent session connections for enabling communication with a number of server systems. Each browser URL is passed to the TPG component that examines a context field within the URL. If the context field has been set to a predetermined value, the TPG component in lieu of opening a new session connection to the designated server system, obtains a pre-established session connection from a session pool.

Abstract: A method and system for facilitating the creation of warehouse requests in a data warehouse system. During the design of the data warehouse tables, a repository tool is used for storing a number of new objects such as source and target databases, source and target tables and warehouse requests that are graphically defined and linked together by an administrator with the repository tool. The resulting visual design is so drawn so as to serve as input for each warehouse request to be generated. The administrator invokes a data replication component that operatively couples to the repository tool signaling that the warehouse request is to be implemented. The data replication component automatically creates the different subcomponents of the request by accessing various links stored by the repository tool and displays a visual representation of the subcomponents and their relationships to each other to the administrator.

Abstract: A method and database organization for use by a plurality of client systems wherein a database contains a plurality of table structures for storing a product directory index and a minimum number of product related information entries utilized in generating a bill of materials document for a particular user designated customer product. The system also includes a selection menu facility component and a data selection component, both of which operatively couple to the database. The selection menu facility component enables an operator to access the product directory index for obtaining a number of key information values pertaining to a particular printed circuit board assembly.

Abstract: A configuration system and method uses a program device containing configuration software for configuring applications to be executed by a processing system through the use of externally provided values corresponding to environment variables that are used to define an execution environment for all of the applications to be executed by the system. The configuration system is used to establish a plurality of configuration file sources to be used in configuring applications wherein the files define a plurality of different operational levels. Each configuration file stores the values representative of a corresponding number of configurable items defining the environment for executing the applications. The values of each level has a pre-established override capability over the values of other levels.

Abstract: A multihomed host system is configured with independent front end processor transport providers, each having its own network protocol stack and each being connected to a different TCP/IP network or subnetwork or to different portions of the same network which in turn connects to an internetnetwork. The host system software includes a TCP/IP Transport Agent located between a sockets interface and the host system's input/output supervisor and driver facilities. The TCP/IP Transport Agent is enhanced to include a FEP Multihoming and Routing component for providing a multihoming capability. The FEP Multihoming and Routing component utilizes a plurality of components which are configured from the same administrator supplied configuration and static routing information furnished to the FEPs for configuring their respective TCP/IP stack facilities.

Abstract: A host system includes a multicache system configured within a host system's memory which has a plurality of local and central cache systems used for storing information being utilized by a plurality of processes running on the system. The central cache system includes an obsolete code management (OCM) component that operates to detect and remove obsolete entries stored within the central cache system. The OCM component operates to remove obsolete code from all the caches when events cause such obsolescence, e.g., data definition language (DDL) statements are executed. In certain situations, by being able to perform such operations during DDL statement processing, the OCM component further enhances overall system operation.

Abstract: A host system includes a multicache system configured within the host system's memory which has a plurality of local and central cache systems used for storing information being utilized by a plurality of processes running on the system. Persistent shared memory is used to store control structure information entries required for operating central cache systems for substantially long periods of time in conjunction with the local caches established for the processes. Such entries includes a descriptor value for identifying a directory control structure and individual sets of descriptors for identifying a group of control structures defining those components required for operating the configured central cache systems. The cache directory structure is used for defining the name of each configured central cache system and for providing an index value identifying the particular set of descriptors associated therewith.

Abstract: The main storage of a system includes a virtual memory space containing a plurality of virtual frame buffers for storing information transferred from disk storage shared by a number of virtual processes being executed by the system. An associated buffer table and aging mechanism includes a buffer table storing a plurality of buffer table entries associated with the corresponding number of virtual buffers used for controlling access thereto and an age table containing entries associated with the buffer table entries containing forward and backward age pointers linked together defining the relative aging of the virtual frame buffers from the most recently used to least recently used. Each buffer table entry has a frequency reference counter which maintains a reference count defining the number of times that its associated virtual buffer has been uniquely accessed by the virtual processes.