Show simple item record

dc.contributor.authorMirsafian, Melicaalsadat
dc.date.accessioned2019-09-20 19:23:13 (GMT)
dc.date.available2019-09-20 19:23:13 (GMT)
dc.date.issued2019-09-20
dc.date.submitted2019-09-11
dc.identifier.urihttp://hdl.handle.net/10012/15098
dc.description.abstractOrdered domains such as numbers and dates are common in real-life datasets. The SQL standard includes an ORDER BY clause to sort the results, and there has been research work on formalizing, reasoning about, and automatically discovering order dependencies among columns in a table. However, a crucial assumption made in research and practice is that the order over a column is syntactic: numbers are ordered numerically, strings lexicographically and dates chronologically. To the best of our knowledge, this work is the first to relax this assumption. We present a generalized definition of order compatibilities that allows semantic orders such as (low, medium, high) or (excellent, very good, good, average, poor). We show that in general, validating whether there exists a semantic order relationship between columns is NP-complete, with some tractable special cases. We give an algorithm to automatically discover semantic order relationships in the data, we provide examples of interesting orders found by our algorithm that were missed by existing algorithms, and we show that the NP-complete validation cases do not occur frequently in practice.en
dc.language.isoenen
dc.publisherUniversity of Waterlooen
dc.subjectdatabasesen
dc.subjectorder dependenciesen
dc.subjectdata profilingen
dc.subjectorder in databasesen
dc.titleSemantic Order Compatibilities and Their Discoveryen
dc.typeMaster Thesisen
dc.pendingfalse
uws-etd.degree.departmentDavid R. Cheriton School of Computer Scienceen
uws-etd.degree.disciplineComputer Scienceen
uws-etd.degree.grantorUniversity of Waterlooen
uws-etd.degreeMaster of Mathematicsen
uws.contributor.advisorGolab, Lukasz
uws.contributor.affiliation1Faculty of Mathematicsen
uws.published.cityWaterlooen
uws.published.countryCanadaen
uws.published.provinceOntarioen
uws.typeOfResourceTexten
uws.peerReviewStatusUnrevieweden
uws.scholarLevelGraduateen


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record


UWSpace

University of Waterloo Library
200 University Avenue West
Waterloo, Ontario, Canada N2L 3G1
519 888 4883

All items in UWSpace are protected by copyright, with all rights reserved.

DSpace software

Service outages