[Nepomuk] Live Queries

[Sebastian Trüg]

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).

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.

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
>