A quick ping about JENA-595
This will improve the filter placement optimization, most significantly
when possible with OPTIONAL.
I'm going to apply it to the codebase and, in theory, it performs all
the optimizations the old code used (the tests all pass or an equivalent
test put in due to slightly different ways to do the same thing). If
anything funny starts happening, I'm sure you'll let JIRA know.
Andy
On 19/11/13 21:39, Andy Seaborne (JIRA) wrote:
[
https://issues.apache.org/jira/browse/JENA-595?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13826970#comment-13826970
]
Andy Seaborne commented on JENA-595:
------------------------------------
The JENA-383 query:
{noformat}
PREFIX ex: <http://example/>
SELECT * WHERE {
?var ex:p1 ?x.
OPTIONAL { ?x ex:p2 ?y. }
FILTER (?var != ex:i)
}
{noformat}
Up to Jena 2.11.0:
{noformat}
(prefix ((ex: <http://example/>))
(filter (= ?var ex:i)
(conditional
(bgp (triple ?var ex:p1 ?x))
(conditional
(bgp (triple ?x ex:p2 ?y))
(bgp (triple ?y ex:p3 ?z))))))
{noformat}
and with patch:
{noformat}
(prefix ((ex: <http://example/>))
(conditional
(filter (= ?var ex:i)
(bgp (triple ?var ex:p1 ?x)))
(conditional
(bgp (triple ?x ex:p2 ?y))
(bgp (triple ?y ex:p3 ?z)))))
{noformat}
The filter is done on the LHS of the outer OPTIONAL.
Improve filter placement optimization
-------------------------------------
Key: JENA-595
URL: https://issues.apache.org/jira/browse/JENA-595
Project: Apache Jena
Issue Type: Improvement
Components: ARQ
Reporter: Andy Seaborne
Assignee: Andy Seaborne
Attachments: JENA-595-FilterPlacement.patch
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