See the following response to this issue on the OpenLink Community Forum https://community.openlinksw.com/t/sparql-slow-if-more-object-value-specified/2064/2 ... post all further questions there ...
> On 26 Oct 2020, at 04:49, William Kisman <yin...@gmail.com> wrote: > > Hi , I am using virtuoso 7 open source edition, > > This query below is fast, it return the result instantly, > > select * > WHERE { > > graph <http://localhost:8890/graph > <http://localhost:8890/graph>> { > > ?catAtt qq:catId ?catId; > qq:caDataType ?caDataType; > qq:showInView ?showInview; > qq:valFormat ?valFormatKey; > qq:multiple ?multiple; > qq:position ?position; > qq:link ?link; > qq:catAttName ?catAttName; > qq:setting ?setting; > qq:flag ?flag; > qq:unit ?caUnit. > > > > > } > } > > > LIMIT 20 > This query is so slow, took 10 seconds for the result, the only difference is > the ?catId is replaced with literal value 1 . I thought this should be faster > because it's more specific. > > select * > WHERE { > > graph <http://localhost:8890/graph > <http://localhost:8890/graph>> { > > ?catAtt qq:catId 1; > qq:caDataType ?caDataType; > qq:showInView ?showInview; > qq:valFormat ?valFormatKey; > qq:multiple ?multiple; > qq:position ?position; > qq:link ?link; > qq:catAttName ?catAttName; > qq:setting ?setting; > qq:flag ?flag; > qq:unit ?caUnit. > > > > > } > } > > > LIMIT 20 > Why is it so ? I am still new to sparql and triplestore, seems like I have to > do some indexing on the object ? > > I have tried creating the GOPS index with, I don't understand about the > Partition part, is using O correct ? What does that partition mean ? Creating > this index has improved the execution for the second query to 4 seconds, but > still too slow for a DBMS. > > CREATE COLUMN INDEX RDF_QUAD_GOPS > ON RDF_QUAD (G, O, P, S) > PARTITION (O VARCHAR (-1, 0hexffff)); > > Btw, does virtuoso stored triplet in the regular RDBMS table ? in the table > DB.DBA.RDF_QUAD ? So virtuoso does not have a native storage of graph ? Or > what I don't understand ? > > Thanks > Best regards, > > William > > > _______________________________________________ > Virtuoso-users mailing list > Virtuoso-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/virtuoso-users
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