Mobile Transaction Supports for DBMS: An Overview

The need for information access and processing in mobile computing environments presents great challenges to database researchers. Apart from advances in wireless communications and device technology, new data management techniques are needed to provide a transparent interaction between fixed and mobile devices in global information systems. A key aspect is to provide a flexible and powerful transaction processing infrastructure that takes into account the peculiarities of mobile computing. Mobile transaction processing shall be able to transparently deal with frequent disconnections and occasional movements of mobile devices. This paper surveys the mobile transaction models proposed in academia and outlines the state-of-the-art of transaction processing in commercial mobile databases.

International Journal of Database Management Systems, 2012

The popularity of the Mobile Database is increasing day by day as people need information even on the move in the fast changing world. This database technology permits employees using mobile devices to connect to their corporate networks, hoard the needed data, work in the disconnected mode and reconnect to the network to synchronize with the corporate database. In this scenario, the data is being moved closer to the applications in order to improve the performance and autonomy. This leads to many interesting problems in mobile database research and Mobile Database has become a fertile land for many researchers. In this paper a survey is presented on data and Transaction management in Mobile Databases from the year 2000 onwards. The survey focuses on the complete study on the various types of Architectures used in Mobile databases and Mobile Transaction Models. It also addresses the data management issues namely Replication and Caching strategies and the transaction management functionalities such as Concurrency Control and Commit protocols, Synchronization, Query Processing, Recovery and Security. It also provides Research Directions in Mobile databases.

… in Parallel and Distributed Systems, 1993., …, 1993

Distributed systems are expected to support mobile computations ezecuted over a computer network of fixed and mobile hosts. This paper examines the re-quirements for structuring such mobile computations that access shared data in a database, argues that open-nesting ...

Proceedings. IDEAS'98. International Database Engineering and Applications Symposium (Cat. No.98EX156), 1998

In this paper, we introduce a prewrite operation before a write operation in a mobile transaction to improve data availability. A prewrite operation does not update the state of a data object but only makes visible the value that the data object will have after the commit of the transaction. Once the transaction has read all the values and declares all the prewrites, it can precommit at mobile host. The remaining transactionÕs execution is shifted to the stationary host. Writes on database consume both time and resources at stationary host and are therefore, delayed. A pre-committed transactionÕs prewrite values are made visible both at mobile and stationary hosts before the final commit of the transaction. This increases data availability during frequent disconnection common in mobile computing. Since the expensive part of the transaction execution is shifted to the stationary host, it reduces the computing expenses at mobile host.

Operations Research/Computer Science Interfaces Series, 2002

Mobile computing paradigm has emerged due to advances in wireless or cellular networking technology. This rapidly expanding technology poses many challenging research problems in the area of mobile database systems. The mobile users can access information independent of their physical location through wireless connections. However, accessing and manipulating information without restricting users to specific locations complicates data processing activities. There are computing constraints that make mobile database processing different from the wired distributed database computing. In this paper, we survey the fundamental research challenges particular to mobile database computing, review some of the proposed solutions and identify some of the upcoming research challenges. We discuss interesting research areas, which include mobile location data management, transaction processing and broadcast, cache management and replication and query processing. We highlight new upcoming research directions in mobile digital library, mobile data warehousing, mobile workflow and mobile web and e-commerce.

International Journal of Modeling and Optimization, 2011

Increasing demand of mobility introduced modern trends towards databases. However, issues on transaction management in mobile database still persist. This paper analyzes the existing models of transaction management in mobile databases and proposes a new model that deals transactions in two phases; one giving complete rights to mobile host for updating data and second, makes use of the computational capabilities of fourth generation mobile devices for databases manipulation irrespective of other networks issues like connectivity and network interoperability. The proposed model reduces transaction commit time by introducing cache at mobile end and treating disconnected mode similar to connecting mode. It further eliminates the short comings of the existing two tiers, IOT, kangaroo, planned disconnection mode and clustering schemes. Index Terms-distributed databases; mobile database systems (MDS); global system for Mobile Communication (GSM); dual phased transaction model Manuscript received March 20, 2011.

… Conference on Parallel …, 1997

Tremendous advances in computer hardware and com-munication have made mobile computing feasible. In this paper, a new transaction management scheme for mobile computing environments is proposed. The proposed scheme attempts to support desired features in the mobile ...

Distributed and Parallel Databases, 2001

We incorporate a prewrite operation before a write operation in a mobile transaction to improve data availability. A prewrite operation does not update the state of a data object but only makes visible the future value that the data object will have after the final commit of the transaction. Once a transaction reads all the values and declares all the prewrites, it can pre-commit at mobile host (MH) (computer connected to unreliable mobile communication network). The remaining transaction's execution (writes on database) is shifted to the mobile service station (MSS) (computer connected to the reliable fixed network). Writes on database consume time and resources and are therefore shifted to MSS and delayed. This reduces wireless network traffic congestion. Since the responsibility of expensive part of the transaction's execution is shifted to the MSS, it also reduces the computing expenses at mobile host. A pre-committed transaction's prewrite values are made visible both at mobile and at fixed database servers before the final commit of the transaction. Thus, it increases data availability during frequent disconnection common in mobile computing. Since a pre-committed transaction does not abort, no undo recovery needs to be performed in our model. A mobile host needs to cache only prewrite values of the data objects which take less memory, transmission time, energy and can be transmitted over low bandwidth. We have analysed various possible schedules of running transactions concurrently both at mobile and fixed database servers. We have discussed the concurrency control algorithm for our transaction model and proved that the concurrent execution of our transaction processing model produces only serializable schedules. Our performance study shows that our model increases throughput and decreases transaction-abort-ratio in comparison to other lock based schemes. We have briefly discussed the recovery issues and implementation of our model.

2005

This document focuses on transaction processing on mobile clients accessing a common set of data. The key requirement is to maintain all transaction properties as far as possible. We discuss three scenarios for databases on mobile clients, summarize typical applications and requirements for each of the three scenarios, and outline open research issues within each of the three scenarios. While the first scenario consists of mobile clients that are connected to a wired network, the second scenario consists of a network of mobile clients with a single-hop distance to each other but without a wired network, and the third scenario considers a network of mobile clients some of which are in multi-hop distance. The focus of our contribution is on distinguishing open problems from known solutions for each of the three scenarios. As the scenarios are increasingly challenging, we have identified additional requirements that occur within each new scenario compared to the previously discussed scenario. ** This document summarizes the results of the working group discussions on "Mobile Transactions" held during the Seminar on Mobile Information Management in October 2004 at Dagstuhl, Germany.

Distributed and Parallel Databases, 2004

Transaction support is crucial in mobile data management. Specific characteristics of mobile environments (e.g. variable bandwidth, disconnections, limited resources on mobile hosts) make traditional transaction management techniques no longer appropriate. Several models for mobile transactions have been proposed but it is difficult to have an overview of all of them. This paper analyzes and compares several contributions to mobile transactions. The analysis distinguishes two groups of models. The first group includes proposals where transactions are completely or partially executed on mobile hosts. In this group we focus on ACID properties support. The second group considers transactions requested by mobile hosts and executed on the wired network. In this case, ACID properties are not compromised and focus is on supporting mobile host movements during transaction execution. Discussions pointing out limitations, interesting solutions and research perspectives complete this paper.