- From: Markus Krötzsch <markus.kroetzsch@comlab.ox.ac.uk>
- Date: Fri, 25 Feb 2011 20:56:09 +0000
- To: Atanas Kiryakov <naso@sirma.bg>
- CC: semantic-web@w3.org, "OWLIM-info@ontotext.com" <OWLIM-info@ontotext.com>
On 25/02/2011 17:40, Atanas Kiryakov wrote: > Dear Markus, > > my second round of comments follow inline Thanks, these clarifications were helpful. Just one question: <snip> >> >> We would be happy with interval restrictions on number and string data. > > At present we do not perform number normalisation and special purpose > indexing. Thus, comparing number literals is done based on their string > representation. Thus, if one needs to do accurate interval searches and > other constraints on numbers, s/he should take care to normalise the > string representation of the numbers in the application. Still, > performance-wise doing such types of constraints on literals is fast > enough for usage scenarios we have seen so far If by normalisation you mean the transformation into the canonical XSD representation, then I do not quite see how lexicographic ordering would give you the same results as numerical ordering. In particular, leading zeros are prohibited in canonical number formats, so numbers 1, 2, 10 would really yield the strings "1", "2" and "10" which would sort lexicographically as "1" < "10" < "2". But in general we would compute the canonical forms of all data anyway before pushing it to any store, so this is not a problem. - Markus -- Dr. Markus Krötzsch Oxford University Computing Laboratory Room 306, Parks Road, Oxford, OX1 3QD, UK +44 (0)1865 283529 http://korrekt.org/
Received on Friday, 25 February 2011 20:59:50 UTC