The demand for real-time e-commerce data services has been increasing recently. In many ecommerce applications, it is essential to process user requests within their deadlines, i.e., before the market status changes, using fresh data reflecting the current market status. However, current data services are poor at processing user requests in a timely manner using fresh data. To address this prob...

In order to respond to real-time data access requirements of the underlying applications, mobile computing systems need to be supported by real-time DBMSs. In this paper, we discuss critical issues related to real-time transaction management in mobile computing systems. We identify some open research problems and suggest directions for future work on possible solution methods. We also present a...

Data Grid is an infrastructure that controls huge amount of data files, and provides intensive computational resources across geographically distributed collaboration. The heterogeneity and geographic dispersion of grid resources and applications place some complex problems such as job scheduling. Most existing scheduling algorithms in Grids only focus on one kind of Grid jobs which can be data...

As discussed in Section 2.1, AT is further divided into two components, namely Probe Wait and Bcast Wait. We argue that it might be more appropriate to divide AT into four components: Index-Probe Wait (IPW), Index-Bcast Wait (IBW), Data-Probe Wait (DPW) and Data-Bcast Wait (DBW). IPW is the same as Probe Wait defined in (Imielinski, 1997), i.e., the time duration of getting to the nearest index...

We present ASYMP, a distributed graph processing system developed for the timely analysis of graphs with trillions of edges. ASYMP has several distinguishing features including a robust fault tolerance mechanism, a lockless architecture which scales seamlessly to thousands of machines, and ecient data access pa‹erns to reduce per-machine overhead. ASYMP is used to analyze the largest graphs at...

Open-architecture machine tool controllers have been an important research subject in both academia and industry. They are hard realtime applications that require a built-in database management system to support concurrent data access and provide well-defined interfaces. These advanced applications often utilize object-oriented models to handle complex data types. Since there exists no agreed-u...

We introduce the Random Access Zipper (RAZ), a simple, purely-functional data structure for editable sequences. The RAZ combines the structure of a zipper with that of a tree: like a zipper, edits at the cursor require constant time; by leveraging tree structure, relocating the edit cursor in the sequence requires log time. While existing data structures provide these time bounds, none do so wi...

A critical issue in mobile data management is to respond to real-time data access requirements of the supported application. However, it is difficult to handle real-time constraints in a mobile computing environment due to the physical constraints imposed by the mobile computer hardware and the wireless network technology. In this paper, we present a mobile database system model that takes into...