[Nepomuk] Live Queries

[Vishesh Handa]

On Fri, May 11, 2012 at 12:49 PM, Sebastian Trüg <trueg at kde.org> wrote:

> I thought about that before. I actually figured we could try some very
> simple heuristics in the query service to analyze the query and
> configure the resourcewatcher accordingly (that reminds me: I already
> converted the query service to the rw - not sure if I ported that to
> kde-runtime though).
>

Screw it. If everything goes according to plan, we're removing
kde-runtime/nepomuk in another week or so.


>
> the simplest heuristic would be to check for ResourceTypeTerm in the
> main AndTerm (or as the only term) and then configure the RW accordingly.
> That might already take care of those main queries.
>

This seems like a good idea.

Don't you think that sometimes one just might not need live queries?
Specially for the timeline stuff like "Yesterday". There is very little
chance of it changing.


> Cheers,
> Sebastian
>
> On 05/11/2012 09:08 AM, Vishesh Handa wrote:
> > Hey Sebastian and Peter
> >
> > I've noticed that in the latest git version of Dolphin, the side-bar has
> > been updated to show cool stuff like all your Documents, Music and even
> > stuff from timeline.
> >
> > Each of these runs by passing a query to the query service client, which
> > in turn passes it the QueryService. The QueryService runs the query AND
> > waits for changes to the Nepomuk repository. The moment it notices that
> > the repository has changed, it re-runs ALL the queries.
> >
> > This gives us absolutely horrible performance when listing a large
> > number of files. A typical example is listing all the music files when
> > stuff is being indexed. I have a small music collection, just around
> > 35,000 songs. Listing all them takes a lot out of Nepomuk and Dolphin.
> > This will become an even more serious issue when the Telepathy-Nepomuk
> > Service is shipped. It writes even the smallest change to Nepomuk, and
> > that results in all the queries being re-run.
> >
> > Is there any way we can improve this?
> >
> > I was hoping for some kind of 'live query' boolean parameter. Only the
> > queries with that parameter set will be re-run. For simple stuff like
> > querying all the music files or documents (or even Timeline) we could
> > use the ResourceWatcher.
> >
> > What do you guys think?
> >
> > --
> > Vishesh Handa
> >
>



-- 
Vishesh Handa
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