44506659
A Process Migration Implementation for a Unix System
41657422
Long-Term Caching Strategies for Very Large Distributed File Systems
29614860
A mobile computer interface for heterogeneous databases
Computer-based personal information services are evolving beyond simple applications such as retrieval of phone numbers to include interaction with collections of large, heterogeneous, geographically distributed information bases. Concurrently, small, pen-based, mobile computers are becoming the machine of choice for personal computing. This latter trend suggests simple interfaces that are easy-to-use, avoid keyboard use, and are suited for the small screens and small memory sizes of mobile machines. The former trend, however, suggests an increased sophistication in database interfaces, so as to provide access to the more complex heterogeneous collection of databases that are now part of a personal information service. At the Matsushita Information Technology Laboratory (MITL) they are working on a pen-based graphical database language that begins to combine these conflicting demands for simplicity and sophistication. The authors sketch the highlights of the research approach, and present a brief description of the current prototype.<<ETX>>
59895916
Concurrency Control and Recovery for Global Procedures in Federated Database Systems
52874049
Negotiating data access in federated database systems
A protocol is presented for negotiating access to data in a federated database. This protocol deals with several important aspects of data sharing in an environment where databases belonging to different organizations coexist and cooperate. It is based on the concept of quasicopies. These are cached values that are allowed to deviate from the central value in a controlled fashion. The degree of consistency of a quasicopy is established by the entity where the quasicopy is to reside. Two techniques are presented that can be used for numerical data and for copies that rely on version numbers. It is believed that these two ideas encompass many of the interesting cases in practice. However, it is also possible to fine tune the estimation of this function once the exact semantics of the data involved are known.<<ETX>>
5881433
An advisor for flexible working sets
The traditional model of virtual memory working sets does not account for programs that can adjust their working sets on demand. Examples of such programs are garbage-collected systems and databases with block cache buffers. We present a memory-use model of such systems, and propose a method that may be used by virtual memory managers to advise programs on how to adjust their working sets. Our method tries to minimize memory contention and ensure better overall system response time. We have implemented a memory “advice server” that runs as a non-privileged process under Berkeley Unix. User processes may ask this server for advice about working set sizes, so as to take maximum advantage of memory resources. Our implementation is quite simple, and has negligible overhead, and experimental results show that it results in sizable performance improvements.
29591299
Trade Press News
42014672
Trade Press News - Announcement and Preface