Unisys Corporation

John R Jordan

Ralph E Sipple

Thomas P Cooper

Ronald Q Smith

James A Elke

Lester Y Lee

James R Mettling

Anthony P vonArx

James M Plasek

Dennis R Konrad

Robert E Swenson

Michael J Hill

Lee-Chin Hsu Liu

James F Torgerson

Jennifer J Smith

Joseph E Kessler

Rajeev P Tandon

Michael J Bierma

Marvin W Theis

Donald T Bordsen

Katsuhiko Kihara

Sheng-te Chiang

John O Sjolander

Robert F Esson

A system for concurrent processing of queries and transactions against a shared database. The system includes multiple processors wherein a processor is available for processing queries and another processor is available for concurrently processing transactions. A query buffer is established for performing the query search while the data accessed by transactions is available in a database cache. Control logic in a database management system distinguishes between transactions and queries and initiates file-read control for reading the file containing the database. File-read control contains logic for logical sequential reading and logical non-sequential reading of the file. Control structures provide a means for control over the load that the query is allowed to place on the system.

System for optimally processing a transaction and a query to the same

A system for parallel reading and processing of a file. The system includes multiple disks for storing the file. The disks are coupled to a data processing system via multiple input-output channels. A file buffer is established in the memory of the data processing system, wherein the file buffer is shared by an instruction processor that initiates a parallel read request and manipulates the file data once it is read, and multiple input-output processors that are coupled to the input-output channels. Multiple input requests are issued to the multiple disks to be processed in parallel. The input-output processors write file data to a first portion of the file buffer in parallel with the reading of a second portion of the file buffer by the instruction processor. Control structures provide a means for control over the input processing demands that the parallel read request is allowed to place on the system.

System for parallel reading and processing of a file

A multiprocessor data processing system is implemented with processors, each of which may request for a temporary time the exclusive lock on an object which is stored on a data base. To achieve this a lock processor synchronizes the locking and unlocking of the objects. The requesting processor directs the storage of the object from the data base into a selected high performance storage unit, where it has exclusive rights to modify or write into the object until the object is unlocked by the processor. An audit tape or disk records all modifications made to any object during a transaction. A non-volatile cache memory is inserted in the audit trail to store a before-look image of the object that resides in the high performance storage unit. Data compaction occurs by comparison of the before-look image with an after-look image to provide a difference image, which is supplied to an audit buffer that is coupled to the audit tape. The locking processor may unlock the secured object once the after-look image has been committed from either a stored version in the non-volatile cache or from a high performance main memory unit to the data base disk. The difference image and the after-look image associated with the difference image may then be stored in the non-volatile cache, and provided to the audit tape or disk and the data base disk in a sequence which is independent of the operating sequence of the requesting processor.

Cache memory with data compaction for use in the audit trail of a data

A record lock processor provides a common facility for control of the locking and unlocking of mass storage objects (for example, records, files, pages or any other logical entity) that is shared by a number of loosely-coupled data processors. The terms 'record' or 'records' wherever they are used in this document are intended to refer to all such objects, including records, files, pages or any other logical grouping or entity into which the mass storage may be portioned. Each of the data processors has access to all of the shared mass storage. Three Lock Modules all receive the same requests and majority voting techniques are used to determine the result. A fourth lock module is included as a Hot Spare Module. A Maintenance Module receives the same requests as the voting Lock Modules and, therefore, it is able to interpret results on-line based on user requests. Programmable Channel Interfaces provide the operational interface to the host processors. The Lock Modules are also programmable, and they hold lock and Queued Lock Requests and execute locking and unlocking algorithms in response thereto.

Record lock processing for multiprocessing data system with majority

A Record Lock Processor is utilized in a multi-host data processing system to control the locking of Objects upon request of each of the multiple host data processors in non-conflicting manner. The Record Lock Processor has storage provisions which include a Lock List for storing bits that identify the Objects and bits that identify the requesting processor, a Queue List that stores entries that are formatted like the Lock List entry when a prior Lock List entry has been made for the same Object, and a Cache List for each processor that stores Cache List entries that identify each Object that is stored in the cache memories, each of which Cache List entries is associated with one of the requesting processors, wherein such Cache List entries include validity bits that identify whether each Object stored in a Cache List has a Valid or an Invalid status.

Locking control with validity status indication for a multi-host

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Saint Paul, MN, United States of America

John R Jordan