Hi Laura!
The string functions are standard SPARQL features and don't rely on a
text index.
The text index is only useful if you need either full text search or
other efficient non-exact types of text matching such as prefix searches.
You can always use FILTERs and string functions, but they can be slow
when you have large amounts of data as they need to be evaluated for
every string in the data.
-Osma
Laura Morales kirjoitti 23.05.2017 klo 09:57:
I'm reading the documentation at
https://jena.apache.org/documentation/query/text-query.html but I don't
understand if this is only for full-text searches. Or should I use one of these
indexes every time I use one the string functions
(https://www.w3.org/TR/sparql11-query/#func-strings) such as CONTAINS, LCASE,
etc.?
--
Osma Suominen
D.Sc. (Tech), Information Systems Specialist
National Library of Finland
P.O. Box 26 (Kaikukatu 4)
00014 HELSINGIN YLIOPISTO
Tel. +358 50 3199529
[email protected]
http://www.nationallibrary.fi
