[jira] [Created] (MARMOTTA-575) SELECT queries over a free subject generated to many CROSS JOINs

["Sergio Fernández (JIRA)" <ji...@apache.org>]

Sergio Fernández created MARMOTTA-575:
-----------------------------------------

             Summary: SELECT queries over a free subject generated to many CROSS JOINs
                 Key: MARMOTTA-575
                 URL: https://issues.apache.org/jira/browse/MARMOTTA-575
             Project: Marmotta
          Issue Type: Improvement
          Components: KiWi Triple Store
    Affects Versions: 3.3.0
            Reporter: Sergio Fernández
             Fix For: 3.4.0


In the typical usage of SPARQL retrieving all properties for a concrete type:

{code:none}
SELECT ?uri ?var1 ?var2 ?varN
WHERE {
  ?uri a ex:type ;
    ex:var1 ?var1 ;
    ex:var2 ?var2 ;
    ex:varN ?varN .
}
{code}

KiWI performs quite bad, because it creates a {{CROSS JOIN}} for each property.

Making the subject fixed is actually a quite fast query.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)