On 07/02/12 19:10, Stephen Allen wrote:
The original query is valid however. I'm a little worried about the
performance implications of writing so much to the log during query
execution. If the recommended log setting for production use is WARN,
maybe we should downgrade this warning to INFO? Or maybe a single
warning per query? Or even eliminate the warning all together? (I
think I'm in favor of the eliminating it).
Makes sense - it is a helpful warning not an error.
It does not occur in other situations:
http://www.w3.org/TR/sparql11-query/#construct
but this does catch people out.
It was useful writing the update system - may its time has passed. It's
a trade off on support costs; it indicates something that the
application writer may well not have intended.
The rewritten query is more efficient.
I'll remove the message as the code is in front of me and do some
cleaning - all the old substitution code can be commented out/removed.
Andy
The SPARQL spec says only: "If any solution produces a triple
containing an unbound variable or an illegal RDF construct, such as a
literal in a subject or predicate position, then that triple is not
included in the output RDF graph." [1]. There is no indication that
it is bad to rely on this behavior when writing your queries.
-Stephen
[1] http://www.w3.org/TR/sparql11-update/#deleteInsert
