Browsing by Author "Ashton, Maurice G."
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Item Book: The Valley of a Thousand Fauna(2018-01-01) Ashton, Maurice G.; Morton, Jason K.; Fisher, Howard J.; Annable, Terry J.Item Co-existence of Transaction and Non Transaction-Managed Activity in a Persistent Object Store(2005-08-01) Ashton, Maurice G.; Henskens, Frans A.Persistent object stores provide an execution environment in which data and its interrelationships are, by default, retained in their original form beyond the lifetimes of the program or programs that created them. Stability mechanisms ensure that such stores always start up in a self-consistent state, even after non-orderly shutdowns that result from events such as power outages or hardware failures. An efficient means of implementing stability uses Directed Dependency Graphs (DDGs) to facilitate execution of user processes in parallel with updates to the durable store image. The authors have previously shown how these DDGs can be extended and used to provide optimistic, transaction-based concurrency control for processes executing in persistent object stores [2].
The management of persistent objects differs from that afforded by conventional DBMS because the entire dataset exists in the same repository. As in conventional systems, it is appropriate that some data is accessed (queried and mutated) independently of the transaction system. In this paper, we examine the issue of interaction between processes that execute under transaction control with those executing independently of the transaction system. Interestingly, this co-existence is achieved without enforcing transaction semantics on the independent activity.
Item Denizens of the Dora : An Inventory of the Fauna of the Dora Creek Catchment, New South Wales(2018-01-01) Morton, Jason K.; Ashton, Maurice G.; Fisher, Howard J.; Annable, Terry J.Denizens of the Dora is an inventory of the vertebrate and invertebrate fauna of the catchment of Dora Creek, NSW, the largest tributary catchment of Lake Macquarie. About 1,600 animal species have been reported from this small area (230 sq. km). This book documents the present composition of the fauna of the catchment and serves as a reference point for assessment of future changes that may come as a result of climate change and the intensification of human activities and impacts. The inventory also highlights the shortfall in knowledge of the invertebrate fauna, both locally and nationally. The inventory will be of use to members of the public interested in knowing what lives in their environment and can be used to narrow the range of possibilities when attempting to identify some bug, bird or beast. The colour photographs illustrate 56 vertebrate and 131 invertebrate species.
Item Graph-based Optimistic Transaction Management(2007-07-01) Ashton, Maurice G.; Henskens, Frans A.In this paper, we introduce and describe directed dependency graph-based transaction and concurrency control (DCC) for persistent (stable, single-level) object-based bulk data management systems. The new technique is optimistic and applicable across a wide range of store sizes, transaction sizes and multi-programming levels. It is also has potential for use in management of transactions in other contexts, for example web services. [From publisher's website]
Item Unified Support for Stability and Bulk Data in a Persistent Store(2000-01-01) Henskens, Frans A.; Ashton, Maurice G.The results of research into the use of a unified set of mechanisms to support store stability and concurrency control is presented. It is shown that the use and extension of the data structures already maintained by the system to support stability provides support for a novel approach to provision of cooperative concurrency control in persistent systems.