[Nepomuk] On limits of terms for a facet

[Alessandro Sivieri]

Hi all,

while experimenting with Sembrowser, I found out that having many tagged
files and/or many tags can bring to long query times, so I was wondering if
we should consider a limit, in the faceted browsing, in the number of
results shown; for now it may just be a problem of query optimization, in
fact the current version asks Soprano for all the tagged files and for all
the tags names, and then for each tag the file count (based on the other
constraints), but I do not know how much this can be optimized.

As related to the question above: I think I missed something in the model
handling, for getting a parallel execution of the query, separated from the
UI thread; the Smartsave model works correctly, so I copied over the code
handling the query execution, which is just a QMetaObject::invokeMethod, and
in the invoked method I'm using the async query from Soprano; however, in
Sembrowser the UI still freezes while loading tags: am I missing something?

(the file is src/tagsfacet.cpp, in Sembrowser on Gitorious)

-- 
Sivieri Alessandro
alessandro.sivieri at gmail.com
http://www.chimera-bellerofonte.eu/
http://www.poul.org/
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