[Virtuoso-users] Query performance issues

[Sebastian Trüg]

Hello,

using a V6 server with default indexes I would like to know why the
following queries are different in performance. The store contains
thousands of different graphs but adding a "graph ?g {}" around all
patterns does not change the execution time.

select * where { ?r a nfo:FileDataObject .
                 ?r nfo:fileName ?f .
                 ?f bif:contains 'breaking' . }

takes a long time to finish - almost a minute.


select * where { ?r nfo:fileName ?f .
                 ?f bif:contains 'breaking' . }

is finished in no time.

I just would like to understand the reasons behind the difference. If
possible also a solution. :)

Cheers,
Sebastian