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UID:e133f295-4e6c-460f-a1da-6ec311fa6ffc
X-WR-CALNAME:[RATIO] Liat Peterfreund
X-WR-TIMEZONE:Europe/Paris
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TZID:Europe/Paris
TZUNTIL:20241027T010000Z
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TZNAME:CET
DTSTART:20221030T030000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RDATE:20231029T030000
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TZNAME:CEST
DTSTART:20220327T020000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RDATE:20230326T020000
RDATE:20240331T020000
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UID:e133f295-4e6c-460f-a1da-6ec311fa6ffc
DTSTAMP:20260407T092210Z
CLASS:PUBLIC
DESCRIPTION:Title: Querying Incomplete Numerical Data: Between Certain and 
 Possible Answers\nPlace: room 178\nAbstract: Queries with aggregation and 
 arithmetic operations\, as well as incomplete data\, are common in real-wo
 rld databases\, but we lack a good understanding of how they should intera
 ct. On the one hand\, systems based on SQL provide ad-hoc rules for numeri
 cal nulls\, on the other\, theoretical research largely concentrates on th
 e standard notions of certain and possible answers which In the presence o
 f numerical attributes and aggregates are often meaningless.\n\nIn this wo
 rk\, we define a principled compositional framework for databases with num
 erical nulls and answering queries with arithmetic and aggregations over t
 hem. We assume that missing values are given by probability distributions 
 associated with marked nulls\, which yields a model of probabilistic bag d
 atabases. We concentrate on queries that resemble standard SQL with arithm
 etic and aggregation and show that they are measurable\, and that their ou
 tputs have a finite representation. Moreover\, since the classical forms o
 f answers provide little information in the numerical setting\, we look at
  the probability that numerical values in output tuples belong to specific
  intervals. Even though their exact computation is intractable\, we show e
 fficient approximation algorithms to compute such probabilities.\n\nThe ta
 lk is based on joint work with Marco Console and Leonid Libkin\, and will 
 be presented in PODS 2023.
DTSTART;TZID=Europe/Paris:20221129T140000
DTEND;TZID=Europe/Paris:20221129T150000
LOCATION:178
SEQUENCE:0
SUMMARY:[RATIO] Liat Peterfreund
TRANSP:OPAQUE
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