Show simple item record

dc.contributor.authorNeumann, Thomas
dc.contributor.authorKemper, Alfons
dc.contributor.editorSeidl, Thomas
dc.contributor.editorRitter, Norbert
dc.contributor.editorSchöning, Harald
dc.contributor.editorSattler, Kai-Uwe
dc.contributor.editorHärder, Theo
dc.contributor.editorFriedrich, Steffen
dc.contributor.editorWingerath, Wolfram
dc.date.accessioned2017-06-30T11:40:46Z
dc.date.available2017-06-30T11:40:46Z
dc.date.issued2015
dc.identifier.isbn978-3-88579-635-0
dc.identifier.issn1617-5468
dc.description.abstractSQL-99 allows for nested subqueries at nearly all places within a query. From a user's point of view, nested queries can greatly simplify the formulation of complex queries. However, nested queries that are correlated with the outer queries frequently lead to dependent joins with nested loops evaluations and thus poor performance. Existing systems therefore use a number of heuristics to unnest these queries, i.e., de-correlate them. These unnesting techniques can greatly speed up query processing, but are usually limited to certain classes of queries. To the best of our knowledge no existing system can de-correlate queries in the general case. We present a generic approach for unnesting arbitrary queries. As a result, the de-correlated queries allow for much simpler and much more efficient query evaluation.en
dc.language.isoen
dc.publisherGesellschaft für Informatik e.V.
dc.relation.ispartofDatenbanksysteme für Business, Technologie und Web (BTW 2015)
dc.relation.ispartofseriesLecture Notes in Informatics (LNI) - Proceedings, Volume P-241
dc.titleUnnesting Arbitrary Queriesen
dc.typeText/Conference Paper
dc.pubPlaceBonn
mci.reference.pages383-402
mci.conference.locationHamburg
mci.conference.date2.-3. März 2015


Files in this item

Thumbnail

Show simple item record