Dear all, Does TDB has a latest benchmarking performance test result? I found a Berlin sparql test benchmarking result. But it reports on 2008.
Thanks, -xiaoshan -----Original Message----- From: Andy Seaborne [mailto:a...@apache.org] Sent: 2021年1月28日 6:26 To: users@jena.apache.org Subject: Re: XPath Duration functions in Jena Hi Harri, https://www.w3.org/TR/xpath-functions-3/#func-subtract-dates The difference of two dates is the duration bwteeen the dates as points on the timeline as a xs:dayTimeDuration. ?age is "P14484DT0H0M0.000S"^^xsd:dayTimeDuration not PnnYnnMnnD A duration is a defined, fixed length of time. There two kinds of durations xs:dayTimeDuration and xs:yearMonthDuration https://www.w3.org/TR/xpath-functions-3/#duration-subtypes where arithmetic and ordering can be meaningfully defined at all. A combination of months and days is not a fixed interval of time because the number of days in a month isn't the same for all months. Only xs:dayTimeDuration defines a duration that is of a well-defined difference of two points on the timeline (ignoring negative leap seconds). Once "xsd:date - xsd:date" is calculated, the duration is a fixed length of time and does not tie back to which dates were used in the calculation. So "P14484D.." is right not "P44Y6m??D" [[ Confusingly the difference of two Gregorian year-months (gYearMonth) is also an xs:dayTimeDuration, and not a xs:yearMonthDuration, not that it is really defined on gYearMonth (section 9.1), because gYearMonth maps to a point on the timeline and the difference is of two points on the timeline. ]] With ?age is "P14484DT0H0M0.000S"^^xsd:dayTimeDuration For the casting to xsd:yearMonthDuration: (had to check this one!) Casting xsd:dayTimeDuration to xsd:yearMonthDuration is defined. https://www.w3.org/TR/xpath-functions-31/#casting-from-primitive-to-primitive https://www.w3.org/TR/xpath-functions-31/#casting-to-durations """ If ST is xs:yearMonthDuration and TT is xs:dayTimeDuration, the cast is permitted and returns a xs:dayTimeDuration with value 0.0 seconds. """ ST is "source type" TT is target type". I don't know the rationale - (a guess - treat like it is selecting fields from PnnYnnMnnDT..) Andy On 27/01/2021 17:16, Harri Kiiskinen wrote: > Dear all, > > This example run with Fuseki 3.17: > > -------------------------------------------------------------------- > PREFIX fn: <http://www.w3.org/2005/xpath-functions#> > PREFIX xsd: <http://www.w3.org/2001/XMLSchema#> > > SELECT ?y ?d (xsd:dayTimeDuration(?age) as ?a1) > (xsd:yearMonthDuration(?age) as ?a2) where { > bind ( xsd:date("1984-12-01") as ?y) > bind ( xsd:date("1944-05-06") as ?d) > bind ((?y-?d) as ?age ) > } > ------------------------------------------------------------------- > > Gives unexpected results: > > ------------------------------------------------------------------ > y,d,a1,a2 > 1984-12-01,1944-05-06,P14484DT0H0M0.000S,P0M > ------------------------------------------------------------------ > > I was expecting the variable "a2" to contain the duration expressed in > Years and Months, but instead it is zero. > > > What am I doing wrong here? > > Best, > > Harri Kiiskinen
