摘要:
A method and computer program product are provided for implementing highly concurrent record insertion in an ordinal number dependent database. Serialized processing is provided with one concurrent task of multiple concurrent tasks allowed to execute, for allocation of ordinal numbers for record insertion. Concurrent validation processing operations of multiple concurrent tasks are enabled for record insertion in the ordinal number dependent database. A set of counter variables are maintained with the database to enable removal of serialization from the validation phase processing operations for record insertion in the ordinal number dependent database.
摘要:
A soft lock mechanism controls access by multiple processes to a shared resource to make simultaneous access an unlikely event, while not necessarily preventing simultaneous access. Preferably, the soft lock contains a next_free_time field, specifying when the soft lock will next be available, and a lock_duration, specifying a sufficiently long interval for most accesses to the resource to complete. The lock is obtained by comparing the current time to next_free_time. If the current time is later than next_free_time, then the lock is obtained immediately, and next_free_time is updated to the current time plus lock_duration. If the current time is before next_free_time, then next_free_time is incremented by lock_duration, and the requesting process waits until the old next_free_time to obtain the lock. No action is required to release the lock.
摘要:
An apparatus and method retrieves a database record from an in-memory database of a parallel computer system using a non-unique key. The parallel computer system performs a simultaneous search on each node of the computer system using the non-unique key and then utilizes a global combining network to combine the local results from the searches of each node to efficiently and quickly search the entire database.
摘要:
A relatively long, narrow defect in a digital image is repaired by identifying an elongated area to be repaired, and by automatically calculating pixel color/shade values within the area to be repaired from pixel values in the vicinity of the perimeter of the elongated area. Preferably, a user identifies an elongated rectangular area to be repaired on an interactive display. The computer automatically generates the pixel coordinates of a pair of parallel lines constituting the opposite long sides of the rectangle, and a set of line segments running between the long sides. The interior pixels of the rectangle are then filled by interpolating color values along each line segment. Since this method is not guaranteed to fill all pixels, the system optionally maintains a map of pixels filled and not filled while performing this method, and after completion, performs an additional step of assigning to any unfilled pixels a value based on the average of all adjacent pixels. For long, narrow defects, particularly those introduced by creasing, the automated digital image repair method herein described generally produces images without significant visually noticeable defects, and does so without undue effort on the part of the user.
摘要:
An apparatus and method to significantly improve performance of SQL function processing through the use of an encoded vector index (EVI). An EVI provides the data necessary to count the number of records in a database that match criteria provided by a SQL function. The resulting count can then be used to determine, from among two or more candidate approaches, an approach to use in processing an SQL function. By processing the EVI symbol table in lieu of more traditional database indexes, and/or in lieu of the database table itself, statistics for SQL functions are generated significantly faster.
摘要:
A method, apparatus and computer program product are provided for verifying integrity of predefined data structures in a computer system. A central software failure map is stored which includes for each of the predefined data structures a corresponding in-flux bit. The corresponding in-flux bit is set in response to a request to update one of the predefined data structures. Then updating of one of the predefined data structures is performed. The corresponding in-flux bit is reset in response to completing the update of the one of the predefined data structures. During recovery, the corresponding in-flux bits are checked to identify any unstable data structures.
摘要:
A method for partitioning keys onto radix tree logical pages and a parallel index page build algorithm in order to provide radix tree build speedup proportional to the number of processors on the system and controlled efficient page utilization. Also, since keys are intelligently partitioned so that a complete set of keys is inserted into a logical page, there is no page overflow during the tree construction and thus page splitting is eliminated. Since radix index trees are really groups of logical pages in which each logical page contains a small tree, the tree is built (with respect to the logical pages) from the bottom up, while within each individual logical page the tree is constructed from the top down. The space required for a logical page is pre-allocated to allow construction of limbs to begin without waiting for the build of their underlying pages to complete.
摘要:
An apparatus and method retrieves a database record from an in-memory database of a parallel computer system using a unique key. The parallel computer system performs a simultaneous search on each node of the computer system using the unique key and then utilizes a global combining network to combine the results from the searches of each node to efficiently and quickly search the entire database.
摘要:
A method and apparatus provide data security on a parallel computer system using virtual private networks. An access setup mechanism sets up access control data in the nodes that describes which virtual networks are protected and what applications have access to the protected private networks. When an application accesses data on a protected virtual network, a network access mechanism determines the data is protected and intercepts the data access. The network access mechanism in the kernel may also execute a rule depending on the kind of access that was attempted to the virtual network. Authorized access to the private networks can be made via a system call to the access control mechanism in the kernel. The access control mechanism enforces policy decisions on which data can be distributed through the system via an access control list or other security policies.
摘要:
A radio receiver includes a voice-only detection mechanism that detects when the current radio station is transmitting mostly voice, and that changes the function of the receiver depending on whether or not the current radio station is transmitting mostly voice. In a first embodiment, the radio receiver mutes its audio output when the voice-only detection mechanism detects a voice broadcast, or mutes its audio output when the voice-only detection mechanism detects a music broadcast. In a second embodiment, the radio receiver changes to a different radio station when a voice-only signal is detected, or when a music signal is detected. The second embodiment preferably includes a spectrum analyzer that can store a frequency spectrum “signature” of a radio signal, and a second tuner that scans the available radio stations for a signal that matches the stored signature.