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https://issues.apache.org/jira/browse/JENA-1138?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15141297#comment-15141297
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A. Soroka commented on JENA-1138:
---------------------------------
No, the only thing about which I was sure was that it would help at least a
little to avoid lots of transactions, not that it would help very much. *grin*
The annoying thing (to me, anyway) here is that it's not overrunning the heap.
It's GC that is the problem. Would you like me to begin working over the new
impl to remove short-lived objects I can find, at the cost of less readable
code? There are places I could do that. Or is this just a big enough data set
that you are comfortable saying that it just needs a little extra heap?
Another thing that could be tried is working on "mutate-in-place" for our use
of persistent data structures, because that would "compress" a lot of the
object graph and might cut down on some short-lived objects, but I would have
to read the code of Dexx more carefully to guess whether that would make much
of a difference.
> java.lang.OutOfMemoryError: GC overhead limit exceeded
> ------------------------------------------------------
>
> Key: JENA-1138
> URL: https://issues.apache.org/jira/browse/JENA-1138
> Project: Apache Jena
> Issue Type: Bug
> Components: Cmd line tools
> Affects Versions: Jena 3.0.1
> Environment: Oracle JDK 1.8.0, Windows 7 64bit
> Reporter: Giovanni Mels
> Labels: performance
> Attachments: sample-data.zip
>
>
> Since 3.0.1 we get {{java.lang.OutOfMemoryError: GC overhead limit exceeded}}
> exceptions when using the {{sparql}} command line tool, even on relative
> small datasets (~1.6 million triples).
> The issue occurs when the dataset is loaded in memory, so before the actual
> query execution.
> {code}
> sparql --query empty.rq --data sample-data.ttl
> {code}
> Where {{empty.rq}} contains:
> {noformat}
> SELECT * WHERE {}
> {noformat}
> This query takes ~20 seconds using Jena 2.13.0 and Jena 3.0.0, it fails with
> 3.0.1 after ~4 minutes with {{java.lang.OutOfMemoryError: GC overhead limit
> exceeded}}
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