“Phan~oma” are records inserted into a concurrently aelected set of records specified by a predicate such that Ihe selection does not eee a transaction conaietent result. The usual locking slrategy is lo lock only czisling records. However, records that satisfy the eeleclion predicate muat be locked even when they are nol present in the database to prevent their insertion. One way to cope with ...

This paper concerns methods to check for atomic-set serializability violations in concurrent Java programs. The straightforward way to encode a reentrant lock is to model it with a context-free language to track the number of successive lock acquisitions. We present a construction that replaces the context-free language that describes a reentrant lock by a regular language that describes a non-...

Lock managers are among the most studied components in concurrency control and transactional systems. However, one question seems to have been generally overlooked: “When there are multiple lock requests on the same object, which one(s) should be granted first?” Nearly all existing systems rely on a FIFO (first in, first out) strategy to decide which transaction(s) to grant the lock to. In this...

Large-scale shared-memory multiprocessors typically have long latencies for remote data accesses. A key issue for execution performance of many common applications is the synchronization cost. The communication scalability of synchronization has been improved by the introduction of queue-based spin-locks instead of Test&(Test&Set). For architectures with long access latencies for global data, a...

BACKGROUND AND OBJECTIVES Concentrated heparin solutions are instilled into the catheter lumens after each hemodialysis session to prevent catheter thrombosis. The heparin lock concentration at many centers has been decreased recently to reduce the risk of systemic bleeding and contain costs. However, the effect of this change on catheter patency is unknown. We compared catheter patency between...

DiSOM [3, 4, 2] is a distributed shared memory system that o ers users an atomic collection of memory cells provided they satisfy certain well-formedness conditions. This report proves the correctness of DiSOM. The system partitions memory into a set of objects and implicitly associates a read-write lock with each object. Users synchronize accesses to these objects explicitly executing synchron...

Processing XML documents in multi-user database management environments requires a suitable storage model, support of typical XML document processing (XDP) interfaces, and concurrency control mechanisms tailored to the XML data model. In this paper, we sketch our prototype native XML database system called XML Transaction Coordinator (XTC) and specify the operations for accessing and modifying ...

As part of the Starburst extensible database project developed at the IBM Almaden Research Center, we designed and implemented a memory-resident storage component that co-exists with Star-burst’s diskoriented storage component. The two storage components share the same common services, such as query optimization, transaction management, etc. However, the memory-resident storage component is fas...

Large-scale shared-memory multiprocessors typically have long latencies for remote data accesses. A key issue for execution performance of many common applications is the synchronization cost. The communication scalability of synchronization has been improved by the introduction of queue-based spin-locks instead of Test&(Test&Set). For architectures with long access latencies for global data, a...

Mass accuracy is a key parameter in proteomic experiments, improving specificity, and success rates of peptide identification. Advances in instrumentation now make it possible to routinely obtain high resolution data in proteomic experiments. To compensate for drifts in instrument calibration, a compound of known mass is often employed. This 'lock mass' provides an internal mass standard in eve...