[jira] [Issue Comment Deleted] (JENA-1257) Bad performance with VALUES blocks

["Andy Seaborne (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/JENA-1257?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Andy Seaborne updated JENA-1257:
--------------------------------
    Comment: was deleted

(was: This appears to be related to the changes for JENA-1171. That introduced deep analysis of the query whereas previous the scope analysis did not look inside EXISTS.
)

> Bad performance with VALUES blocks
> ----------------------------------
>
>                 Key: JENA-1257
>                 URL: https://issues.apache.org/jira/browse/JENA-1257
>             Project: Apache Jena
>          Issue Type: Bug
>          Components: ARQ
>    Affects Versions: Jena 3.1.1
>         Environment: Ubuntu 12.04 LTS amd64
> java version "1.8.0_91" (Oracle)
>            Reporter: Osma Suominen
>              Labels: performance
>         Attachments: explain.zip
>
>
> I'm having performance issues with a query involving VALUES blocks. It seems to me that the values are bound to variables too late, which causes long execution times.
> Also discussed on users list: http://mail-archives.apache.org/mod_mbox/jena-users/201611.mbox/%3c58185A49.7060100@helsinki.fi%3e
> Steps to repeat:
> 1. Create a TDB with YSO:
> {noformat}
> wget http://api.finto.fi/download/yso/yso-skos.ttl
> tdbloader --loc YSO yso-skos.ttl
> {noformat}
> 2. Run the below query against the TDB:
> {noformat}
> tdbquery --loc YSO --query ysoslowunion.rq
> {noformat}
> Contents of ysoslowunion.rq:
> {noformat}
> PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
> SELECT *
> WHERE {
>   VALUES ?uri { <http://www.yso.fi/onto/yso/p864> }
>   { ?s ?p ?uri }
>   UNION
>   { ?uri ?p ?o 
>     OPTIONAL {
>       ?x skos:member ?o .
>       FILTER NOT EXISTS {
>         ?x skos:member ?other .
>         FILTER NOT EXISTS {
>           ?other skos:broader ?uri
>         }
>       }
>     }
>   }
> } 
> {noformat}
> With Jena 3.1.0 this takes <1 second.
> With current 3.1.1 snapshot it takes 12 seconds.
> Possibly related to changes made in JENA-1167.
> I will attach --explain output for both versions as a zip. The 3.1.1 output is 473 MB uncompressed.



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