hi, Zhenquiang On 3/12/10, Chen, Zhenqiang <[email protected]> wrote: > > I have lots of photos. I want to get part of them after sorting. I use > series of queries like: > > tracker-sparql -q "SELECT ?photo WHERE{?photo a nmm:Photo} ORDER BY > ASC(?photo) OFFSET 1000 LIMIT 100" > ... > tracker-sparql -q "SELECT ?photo WHERE{?photo a nmm:Photo} ORDER BY > ASC(?photo) OFFSET 2000 LIMIT 100" > > "Order" seams expensive in tracker. > How to use index? What's the best way to do it?
Those queries look pretty useless, you are getting a list of sorted uris of pictures (generated uris, not even the real location). You are sorting a list like "urn:uuid:1273628", "urn:uuid:98377273", ... your usage of offse and limit is fine though. We cannot help with the performance of such a "laboratory" query. could you try with a more realistic example? regards, ivan > Thanks! > -Zhenqiang > _______________________________________________ tracker-list mailing list [email protected] http://mail.gnome.org/mailman/listinfo/tracker-list
