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DTSTART:20141026T030000
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RDATE:20151025T030000
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UID:calendar.7024.field_data.0@www.diag.uniroma1.it
DTSTAMP:20260417T045348Z
CREATED:20150403T142530Z
DESCRIPTION:Incomplete data is ubiquitous: the more data we accumulate and 
 the more widespread tools for integrating and exchanging data become\, the
  more instances of incompleteness we have. And yet the subject is poorly h
 andled by both practice and theory. Many queries for which students get fu
 ll marks in their undergraduate courses will not work correctly in the pre
 sence of incomplete data\, but these ways of evaluating queries are cast i
 n stone – SQL standard. We have many theoretical results on handling incom
 plete data but they are\, by and large\, about showing high complexity bou
 nds\, and thus are often dismissed by practitioners. Even worse\, we have 
 a basic theoretical notion of what it means to answer queries over incompl
 ete data\, and yet this is not at all what practical systems do. Is there 
 a way out of this predicament? Can we have a theory of incompleteness that
  will appeal to theoreticians and practitioners alike\, by explaining inco
 mpleteness and being at the same time implementable and useful for applica
 tions? After giving a critique of both the practice and the theory of hand
 ling incompleteness in databases\, the paper outlines a possible way out o
 f this crisis. The key idea is to combine three hitherto used approaches t
 o incompleteness: one based on certain answers and representation systems\
 , one based on viewing incomplete databases as logical theories\, and one 
 based on orderings expressing relative value of information.
DTSTART;TZID=Europe/Paris:20150408T090000
DTEND;TZID=Europe/Paris:20150408T090000
LAST-MODIFIED:20240620T113644Z
LOCATION:Aula Magna\, DIAG
SUMMARY:Incomplete Data: What Went Wrong\, and How to Fix It - Leonid Libki
 n\, University of Edinburgh
URL;TYPE=URI:http://www.diag.uniroma1.it/node/7024
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