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Aggregate computation, such as selecting the minimum attribute value of a relation, is expensive, especially in a temporal database. We describe the basic techniques behind computing aggregates in conventional databases and show that these techniques are not efficient when applied to temporal databases. We examine the problem of computing constant intervals(More)
This docuinent specifies a temporal extension to the SQL-92 language standard. The language is designated TSQLZ. The document is organized as follows. The next section indicates the starting point of the design, the SQL92 language. Section 4 lists the desired features on which the TSQL2 Language Design Committee reached consensus. Section 5 presents the(More)
This document contains de nitions of a wide range of concepts speci c to and widely used within temporal databases. In addition to providing de nitions, the document also includes explanations of concepts as well as discussions of the adopted names. The consensus e ort that lead to this glossary was initiated in Early 1992. Earlier versions appeared in(More)
This tutorial presents the primary constructs of the consensus temporal query language TSQL2 via a media planning scenario. Media planning is a series of decisions involved in the delivery of a promotional message via mass media. We will follow the planning of a particular advertising campaign. We introduce the scenario by identifying the marketing(More)
1 School of EECS, Washington State University {burgun,cdyreson}@eecs.wsu.edu 2 Department of Computer Science, University of Arizona rts@cs.arizona.edu 3 Department of Computer Science, University of Washington jessica@cs.washington.edu 4 Microsoft Corporation, Redmond, WA, nkline@microsoft.com 5 Amazon.com, Seattle, WA, soo@amazon.com 6 Department of(More)
We propose a temporal dependency, called trend dependency (TD), which captures a signi cant family of data evolution regularities. A simple example of such regularity might be: \Salaries of employees do not decrease." TDs compare attributes over time using operators of f<;=;>; ; ; 6=g. We de ne a satis ability problem that is the dual of the logical(More)