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https://issues.apache.org/jira/browse/JENA-2020?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17255227#comment-17255227
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Andy Seaborne edited comment on JENA-2020 at 12/27/20, 2:03 PM:
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In my case, I am adding a new operator OpExistence in a transformation of
OpBGP. This would make the query plan look like below:
{noformat}
(existence
(bgp
(triple a b c)
(triple d e f)
)
)
{noformat}
So when I say "before", it is because I read the existence tag before the bgp
tag in the query plan. So, in my understanding, the QueryIterator passed to the
evaluation step for OpExistence is the QueryIterator returned from OpBGP, since
OpBGP is one level lower in the execution tree than OpExistence. Is that
correct?
was (Author: mrpekar):
In my case, I am adding a new operator OpExistence in a transformation of
OpBGP. This would make the query plan look like below:
{noformat}
(existence
(bgp
(triple a b c)
(triple d e f)
)
)
noformat}
So when I say "before", it is because I read the existence tag before the bgp
tag in the query plan. So, in my understanding, the QueryIterator passed to the
evaluation step for OpExistence is the QueryIterator returned from OpBGP, since
OpBGP is one level lower in the execution tree than OpExistence. Is that
correct?
> Purpose of EvaluatorSimple and OpExecutor
> -----------------------------------------
>
> Key: JENA-2020
> URL: https://issues.apache.org/jira/browse/JENA-2020
> Project: Apache Jena
> Issue Type: Question
> Components: ARQ
> Reporter: Martin Pekár
> Priority: Major
> Original Estimate: 1h
> Remaining Estimate: 1h
>
> I am in the midst of adding a new operator in the transformation of OpBGP. I
> am now trying to implement the execution of the operator in the query plan,
> but I am now slightly confused about the purpose of EvaluatorSimple used in
> EvaluatorDispatch and OpExecutor. At the moment, it seems like they are doing
> the same thing. The difference seems to be that OpExecutor stores the result
> of applying the operator in a QueryIterator, whereas EvaluatorSimple stores
> its result in a Table of bindings.
> Can someone give me an explanation of purposes of these two classes and how
> they should be used?
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