I just noticed this and it reminded me of an issue I've had with
collapsed faceting with an older version of the patch in Solr 1.3.
Would it be possible, if we can get the terms for all the collapsed
documents on a field, to then facet each collapsed document on the
unique terms it has collectively? What I mean is for example:
Doc 1, 2, 3 collapse together on some other field
Doc 1 is the "main document" and has the "colors" blue and red
Doc 2 has red
Doc 3 has green
For the purposes of faceting, it would be ideal in our case for
faceting on color to count one each for blue, red, and green on this
document (the user drills down on this value to yet another collapsed
set). Right now, when you facet after collapse you just get blue and
red (green is dropped because it collapses out). To the user it makes
the counts seem inaccurate, like they're missing something. Instead
we facet before collapsing and get an "inflated" value (which ticks 2
for red - but when you drill down, you still only get 1 because Doc 1
and Doc 2 collapse together again). Either way it's not ideal.
At the time (many months ago) there was no way to account for this but
it sounds like this patch could make it possible, maybe.
Thanks!
--
Steve
On Sep 5, 2009, at 5:57 AM, Uri Boness wrote:
There's work on the patch that is being done now which will enable
you to ask for specific field values of the collapsed documents
using a dedicated request parameter. This work is not committed yet
to the latest patch, but will be very soon. There is of course a
drawback to that as well, the collapsed documents set can be very
large (depends on your data of course) in which case the returned
result which includes the fields values can be rather large, which
will impact performance, this is why this feature will be enabled
only if you specify this extra parameter - by default no field
values will be returned.
AFAIK, the latest patch should work fine with the latest build.
Martijn (which is the main maintainer of this patch) tries to keep
it up to date with the latest builds. But I guess the safest way is
to work with the nightly build of the same date as the latest patch
(though I would give it a try first with the latest build).
BTW, it's not an official suggestion from the Solr development team,
but if you ask me, if you have to choose now whether to use 1.3 or
1.4-dev, I would go for the later. 1.4 is supposed to be released in
the upcoming week or two and it bring loads of bug fixes,
enhancements and extra functionality. But again, this is my personal
suggestion.
cheers,
Uri
