Hi Stefan,
Within each GRAPH block there is a light amount of optimization (picking
the first, most grounded tripe pattern; avoiding rdf:type) by default.
There isn't anything across GRAPH blocks.
TDB2 is the same as TDB1 in this regard (TDB2 is reworking the storage
and transactions, not th
Are you using TDB?
This page:
https://jena.apache.org/documentation/tdb/optimizer.html
gives some info about how TDB uses statistics to reorder queries. To my understanding (Andy can correct) graphs are not
taken into account. TDB2 may be different...
For other cases-- the transactional in-m
Maybe this article can help:
http://wwwconference.org/www2008/papers/pdf/p595-stocker1.pdf
It's about BGPs not graph patterns, but I guess selectivity still applies.
On Wed, 25 Oct 2017 at 03.17, Dimov, Stefan wrote:
> Let’s consider the following JOIN:
>
> SELECT $subj
> FROM NAMED ng1
> FROM
Let’s consider the following JOIN:
SELECT $subj
FROM NAMED ng1
FROM NAMED ng2
{
GRAPH ng1 { $subj $pred0 $obj0 }
GRAPH ng2 { $subj $pred1 $obj1 }
}
My question is: Does the order of the clauses affect the performance? Let’s say
that ng1 is much bigger than ng2. If SPARQL ap
