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Chapter 1 STQL — A SPATIO-TEMPORAL QUERY LANGUAGE
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@MISC{Erwig_chapter1,
author = {Martin Erwig and Markus Schneider},
title = {Chapter 1 STQL — A SPATIO-TEMPORAL QUERY LANGUAGE},
year = {}
}
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Abstract
Abstract Integrating spatio-temporal data as abstract data types into already existing data models is a promising approach to creating spatio-temporal query languages. Based on a formal foundation presented elsewhere, we present the main aspects of an SQL-like, spatio-temporal query language, called STQL. As one of its essential features, STQL allows to query and to retrieve moving objects which describe continuous evolutions of spatial objects over time. We consider spatiotemporal operations that are particularly useful in formulating queries, such as the temporal lifting of spatial operations, the projection into space and time, selection, and aggregation. Another important class of queries is concerned with developments, which are changes of spatial relationships over time. Based on the notion of spatio-temporal predicates we provide a framework in STQL that allows a user to build more and more complex predicates starting with a small set of elementary ones. We also describe a visual notation to express developments.
Keyphrases
stql spatio-temporal query language spatio-temporal query language abstract integrating spatio-temporal data data model complex predicate promising approach elementary one spatial operation spatial object spatio-temporal predicate spatial relationship spatiotemporal operation continuous evolution temporal lifting abstract data type formal foundation visual notation important class small set main aspect essential feature
