International Business Machines Corporation

Robert O Dryfoos

Shawfu Chen

Allan Feldman

Arun Kwangil Iyengar

Peter Grimm Sutton

Paul Michael Dantzig

Sastry Duri

Mei-Hui Wang

Jason A Keenaghan

David Y Hu

Peter A Lewis

Mark Richard Gambino

Michael J Shershin

Bradd A Kadlecik

Colette Manoni

James V Farmer

Robert A Blackburn

Glenn W Sears, Jr

Alice M Williams-Obleton

Francis Nicholas Parr

Christopher Daniel Filachek

John M Tarby

Richard J Matela, Jr

Daniel S Gritter

Stephen E Record

Wei-Yi Xiao

Gerald B Strait

Mark A Lehrer

Masashi E Miyake

Steven Edwin Roach

Gary A Fisher, Sr

Leslie F Sutton

Kenneth H Warner

Barry M Baker

Richard E Reynolds

Susan Anderson Pavlakis

Dennis Fallon

Mark Spies

Sunil Shenoi

James S Tison

Yuk S Tam

Theodore Goetz

Ian J Kupfer

Ric C Hung

A method for implementing defragmentation of a data area is provided. The method includes receiving a data change event for the data area and determining, whether the data area has exceeded a defragment threshold based on a defragment threshold value. The method may further include adding the data area to a candidacy list when the data area is determined to have exceeded the defragment threshold based on the defragment threshold value. The method may also include defragmenting the data area when the data area is determined to have exceeded the defragment threshold based on the defragment threshold value and removing the data area from the candidacy list following the determination.

Data fragmentation tuning and candidacy persistence

Techniques are provided for replicating database contents to network-enabled remote systems, and limiting such replication with respect to sensitive database contents. An indication is received that a subset of record fields in a database comprise sensitive data. The subset of indicated record fields are flagged based on the received indication. At least a portion of the database is replicated to multiple remote systems, such that for at least a first of the remote systems, data associated with a larger plurality of record fields is provided to the remote system. For at least a second of the remote systems, based on the flagging of the subset of indicated record fields, only data associated with record fields other than the flagged subset is provided to the remote system.

Protecting sensitive information when replicating data to remote systems

Embodiments of the present invention manage multiple requests to allocate real world resources in a multi-user environment. A set of resource availability information is stored in a first durable data file for each resource in a plurality of resources provided by a database environment. The database environment is shared between a plurality of users. A decision context is associated with a second durable data file. The decision context is associated with a user interacting with the database environment. The decision context exists for a defined duration of time. A least one resource is determined to have been temporarily allocated to the decision context for the defined duration of time. The second durable data file is updated to indicate that the at least one resource has been temporarily allocated to the decision context. The first durable data file is updated to indicate that the at least one resource is currently unavailable.

Supporting linked multi-user decision making in environments with constrained shared resources utilizing durable files

Embodiments of the present invention manage multiple requests to allocate real world resources in a multi-user environment. A request for interacting with a database environment comprising records of allocations of a plurality of resources is received from a user in a plurality of users. The database environment is shared between the plurality of users. A set of action choices available for the request is provided to the user via the user interface. A set of resources required by each action choice is identified. The set of resources is associated with a decision context. The decision context exists for a period of time. The set of resources are allocated to the user for a duration of the decision context. The allocating prevents the set of resources from being allocated to other users for the duration of the decision context irrespective of a set of actions performed by the other users.

Supporting linked multi-user decision making in environments with constrained shared resources

A method for implementing defragmentation of a data area is provided. The method may include receiving a data change event for the data area and determining, whether the data area has exceeded a defragment threshold based on a defragment threshold value. The method may further include adding the data area to a candidacy list when the data area is determined to have exceeded the defragment threshold based on the defragment threshold value. The method may also include defragmenting the data area when the data area is determined to have exceeded the defragment threshold based on the defragment threshold value and removing the data area from the candidacy list following the determination.

A method and system is disclosed for dispatching tasks to multiple processors that all share a shared memory. A composite queue size for multiple work queues each having an associated processor is determined. A queue availability flag is stored in shared memory for each processor work queue and is set based upon the composite queue size and the size of the work queue for that processor. Each queue availability flag indicates availability or unavailability of the work queue to accept new tasks. A task is placed in a selected work queue based on that work queue having an associated queue availability flag indicating availability to accept new tasks. The data associated with task dispatching is maintained so as to increase the likelihood that valid copies of the data remain present in each processor's local cache without requiring updating do to their being changed by other processors.

Task dispatching based on composite queue size and upper and lower compare values

A method of dynamic linkage including: receiving a request to launch a program; checking a system memory for the program; reserving a unique memory block of the system memory for the program and loading the program into the unique memory block if the program is not found in the memory of the system; performing internal memory relocations for the program if the program is not found in the memory of the system; ensuring that a library required by the program has been loaded into the system memory if the program is not found in the memory of the system; and invoking the program.

Methods, systems and computer program products for dynamic linkage

Various embodiments of the present invention allow concurrent accesses to a cache. A request to update an object stored in a cache is received. A first data structure comprising a new value for the object is created in response to receiving the request. A cache pointer is atomically modified to point to the first data structure. A second data structure comprising an old value for the cached object is maintained until a process, which holds a pointer to the old value of the cached object, at least one of one of ends and indicates that the old value is no longer needed.

Managing concurrent accesses to a cache

A common symbol table is generated, which includes symbols of a plurality of independent applications. The symbols included in the common symbol table are common symbols of the applications. The bulky information associated with the common symbols are stored in the common symbol table, and stubs used to locate the common symbols are stored in local tables of the applications.

Generating a common symbol table for symbols of independent applications

A method and system is disclosed for selecting a work queue associated with a processor within a multiple processor architecture to assign a new task. A local and a remote queue availability flag is maintained to indicate a relative size of work queues, in relationship to a mean queue size, for each processor in a multiple processor architecture. In determining to which processor to assign a task, the processor evaluates its own queue size by examining its local queue availability flag and evaluates other processor's queue sizes by examining their remote queue availability flags. The local queue availability flags are maintained asynchronously from task assignment. Remote flags are maintained at time of task assignment. The presented algorithm provides improved local processor queue size determinations in systems where task distribution processes execute with lower priorities that other tasks.

Work queue selection on a local processor within a multiple processor architecture

A method for identifying a set of records in a database for relocation during an on-line database reorganization (ODBR) process. The relocating includes, for each of the records in the set: requesting a record reorganization lock (RRL) on the record, receiving the RRL, retrieving data from the current location of the record, storing the data in the new location of the record, and releasing the RRL. A request is received to update a target record in the set of records with updated data. The receiving of the request is from an application and overlaps in time with at least a portion of the relocating. Independent of the application, a RRL is received on the target record and the target record is updated by writing target data to the target record in the current location and writing the target data to the target record in the new location.

Collision detection and data corruption protection during an on-line database reorganization

Various embodiments of the present invention manage concurrent accesses to a resource in a parallel computing environment. A plurality of locks is assigned to manage concurrent access to a plurality of parts of a resource. A usage of at least one of the plurality of parts of the resource is monitored. The assignment of the plurality of locks to the plurality of parts of the resource is modified based on the usage that has been monitored.

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Hopewell Junction, NY, United States of America

Robert O Dryfoos