.~ Concurrency (e.g., lock management in shared database)
DEFINITION
Classification: 707/8
Concurrency (e.g., lock management in shared database):
(under subclass 1) Subject matter directed to serialization of multiple accesses to the same unit of data or file for the purpose of data integrity.
(1) Note. Concurrency is related to controlling the ability of a plurality of users to simultaneously access the same (i.e., a single unit or copy of) information or proximately located information stored in a database or file (i.e., the ability to control "sharing" of information). Such control may involve the prioritizing or serializing of access to the "shared" information, or the copying of information into independent copies, which must ultimately be "integrated" for data coherency. Coherency, on other hand, although a related topic, is related to the maintaining of multiple copies of information in a database or file in a manner which ensures data integrity amongst the plurality of copies, regardless of whether a single user or plurality of simultaneous users are accessing the information. When a plurality of users are accessing the plurality of copies of information, then both concurrency and coherency concepts may be involved, and the subject matter may be properly classified herein based on hierarchy. Database or file coherency, per se, is classified elsewhere. Source code version management and software version management are classified elsewhere.
(2) Note. For clarification, the methods of ensuring data concurrency include employing time-stamping, semaphores, global and local shared locking (i.e., read only), and exclusive locking (i.e., read and write), multiple versioning, and temporal versioning, such as snapshots.
(3) Note. This subclass is directed to data integrity in database accessing and control. A concept search on this subject or the related subjects of data coherency and version management should consider the related topics as they appear in this class.
SEE OR SEARCH THIS CLASS, SUBCLASS:
511, for document version management under document processing.
SEE OR SEARCH CLASS
345, Computer Graphics Processing, Operator Interface Processing, and Selective Visual Display Systems, 327, 332 for operator interface aspects of workgroup data processing environments for plural users or sites and subclass 971 for a cross-reference art collection directed to interface aspects of cooperative decision support systems for groups of users.
395, Information Processing System Organization,
676, for identifying and dealing with runtime dependencies between executing programs, tasks, processes (e.g., data dependencies, control flow dependencies, etc.), subclass 703 for source code version management in a software programming environment, subclass 712 for software installation and version management of operating systems, application programs, and other executable programs, and subclass 726 for access locking.
705, Data Processing - Financial, Business Practice, Management, or Cost/Price Determination,
1, 45 for automated financial or business practice or management systems and in particular subclasses 1 through 6 for file and database maintenance systems including data coherency in database systems.
711, Electrical Computers and Digital Processing Systems - Memory,
141, 146 for cache memory data coherency, and subclasses 147 through 153 for sharing memory and prioritized access regulation.
