[Nepomuk] Live Queries

[Sebastian Trüg]

On 05/11/2012 09:23 AM, Vishesh Handa wrote:
> 
> 
> On Fri, May 11, 2012 at 12:49 PM, Sebastian Trüg <trueg at kde.org
> <mailto: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.

Yes, you are right. Let's do both.

> 
> 
>     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
>