[Nepomuk] Live Queries

[Vishesh Handa]

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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.kde.org/pipermail/nepomuk/attachments/20120511/288fe5bc/attachment.html>