A two-phase approach to predictably scheduling real-time transactions

Abstract We consider the problem,of designing a database system,that schedules,ACID transactions to meet real-time deadlines. Two complementary algorithms are proposed, valid for a large class of applications, that minimize the unproductive data contention and limit to one the number,of transaction aborts and subsequent retries arising from,achieving,serializability in concurrent execution. This is a crucial step in providing predictable,transaction scheduling,capability for real-time needs. Both algorithms proposed envision two phases,of transaction execution, a first phase that gathers needed information to make the transaction predictable, and a second phase where transactions are scheduled for execution so as to avoid data and,resource,contention. The,two algorithms,together make,up what we call the "TwoPhase Approach". 1 Introduction: The ,Value ,of Real-Time ,Transactions There have,been,a number,of papers in recent years addressing,the problems,of scheduling