it's a common spatial access method latency in paticular for small data sets. you can try a mbr range query instead.
see Chapter 13 Managing Space and Time in Semantic Web Programming by John Hebeler et. al.. 2009 On Fri, Dec 18, 2015 at 10:13 AM, Mark Wharton <[email protected]> wrote: > Hi Jena users. > > I'm having performance problems with a query that uses text and location > search > > The query is roughly this: > > > SELECT ?score ?ent > WHERE { > ?ent spatial:nearby(51.507999420166016 -0.10999999940395355 > 70.01807880401611 'km') . > (?ent ?score) text:query ('environment' 'lang:en') . > ?ent rdf:type iotic:Entity . > } > > > There are about 450 entities in that radius > There are about 2200 entities with environment in their rdfs:comment > > The query takes 5 seconds. > > I've tried this: > Commenting out the text predicate the query takes 97 ms > Commenting out the spatial predicate the query takes 438 ms > Swapping the spatial and text predicates it takes 15 seconds > > > My question is this... It looks like the query is separately getting > the results of the first two predicates and merging (somehow) to find > the intersection. Is there a formulation which will intersect the two > sets faster? > > Many TIAs, > > Mark > -- > Technology Lead, Iotic Labs > [email protected] > https://www.iotic-labs.com -- --- Marco Neumann KONA
