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V. Savenkov, R. Pichler, C. Koch:
"Loop Elimination for Database Updates";
Vortrag: 29th British National Conference on Databases, BNCOD 2013, Oxford, UK; 08.07.2013 - 10.07.2013; in: "Big Data - 29th British National Conference on Databases, BNCOD 2013, Oxford, UK, July 8-10, 2013. Proceedings", G. Gottlob, G. Grasso, D. Olteanu, C. Schallhart (Hrg.); Springer, 7968 (2013), ISBN: 978-3-642-39466-9; S. 48 - 61.

The additional expressive power of procedural extensions of query and update languages come at the expense of trading the efficient set-at-a-time processing of database engines for the much less efficient tuple-at-a-time processing of a procedural language. In this work, we consider the problem of rewriting for-loops with update statements into sequences of updates which do not use loops or cursors and which simultaneously carry out the action of several loop iterations in a set-at-a-time manner. We identify idempotence as the crucial condition for allowing such a rewriting. We formulate concrete rewrite rules for single updates in a loop and extend them to sequences of updates in a loop.

Database updates, Update loops, Query translation

http://dx.doi.org/10.1007/978-3-642-39467-6_8

http://link.springer.com/chapter/10.1007%2F978-3-642-39467-6_8

Projektleitung Reinhard Pichler:
Heterogene Information Integration