With the advances in mobile computing technology,there is an increasing demand for processing real-timetransactions in a mobile environment. This paper proposes a multi-version data model. Based on this data model, wepresent a relative timing correctness criterion for real-time transactions in a mobile environment. As long as the datastaleness is in a controlled extent,it is unnecessary for all the accessed data are valid when a real-time transactioncommits. Also this paper gives a transaction execution model based on the image transaction concept. All these strate-gies not only decreas the cost for the transaction concurrency control,but also increase the possibility to meet mobilereal-time transactions' deadlines by sacrificing the relatively transaction timing correctness. This is in accordance withthe real-time transaction property that a relatively correct and in-time result is more preferable than an absolutely cor-rect but obsolete result.
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