Thanks, I agree this powerful stuff. One of the reasons that I haven't
gotten back to pluggable collectors is that I've been using PostFilters
instead.
When you start doing stuff with scores in postfilters you'll run into the
bug in SOLR-5416. This will effect you when you use facets in combination
with the QueryResultCache or tag and exclude faceting.
The patch in SOLR-5416 resolves this issue. You'll just need your
PostFilter to implement ScoreFilter and the SolrIndexSearcher will know how
to handle things.
The DelegatingCollector.finish() method is so new, these kinds of bugs are
still being cleaned out of the system. SOLR-5416 should be in Solr 4.7.
On Thu, Dec 12, 2013 at 12:54 PM, Peter Keegan <peterlkee...@gmail.com>wrote:
> This is pretty cool, and worthy of adding to Solr in Action (v2) and the
> other books. With function queries, flexible filter processing and caching,
> custom collectors, and post filters, there's a lot of flexibility here.
>
> Btw, the query times using a custom collector to scale/recompute scores is
> excellent (will have to see how it compares to your outlined solution).
>
> Thanks,
> Peter
>
>
> On Thu, Dec 12, 2013 at 11:13 AM, Joel Bernstein <joels...@gmail.com>
> wrote:
>
> > The sorting is going to happen in the lower level collectors. You need a
> > value source that returns the score of the document being collected.
> >
> > Here is how you can make this happen:
> >
> > 1) Create an object in your PostFilter that simply holds the current
> score.
> > Place this object in the SearchRequest context map. Update object.score
> as
> > you pass the docs and scores to the lower collectors.
> >
> > 2) Create a values source that checks the SearchRequest context for the
> > object that's holding the current score. Use this object to return the
> > current score when called. For example if you give the value source a
> > handle called "score" a compound function call will look like this:
> > sum(score(), field(x))
> >
> > Joel
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > On Thu, Dec 12, 2013 at 9:58 AM, Peter Keegan <peterlkee...@gmail.com
> > >wrote:
> >
> > > Regarding my original goal, which is to perform a math function using
> the
> > > scaled score and a field value, and sort on the result, how does this
> fit
> > > in? Must I implement another custom PostFilter with a higher cost than
> > the
> > > scale PostFilter?
> > >
> > > Thanks,
> > > Peter
> > >
> > >
> > > On Wed, Dec 11, 2013 at 4:01 PM, Peter Keegan <peterlkee...@gmail.com
> > > >wrote:
> > >
> > > > Thanks very much for the guidance. I'd be happy to donate a working
> > > > solution.
> > > >
> > > > Peter
> > > >
> > > >
> > > > On Wed, Dec 11, 2013 at 3:53 PM, Joel Bernstein <joels...@gmail.com
> > > >wrote:
> > > >
> > > >> SOLR-5020 has the commit info, it's mainly changes to
> > SolrIndexSearcher
> > > I
> > > >> believe. They might apply to 4.3.
> > > >> I think as long you have the finish method that's all you'll need.
> If
> > > you
> > > >> can get this working it would be excellent if you could donate back
> > the
> > > >> Scale PostFilter.
> > > >>
> > > >>
> > > >> On Wed, Dec 11, 2013 at 3:36 PM, Peter Keegan <
> peterlkee...@gmail.com
> > > >> >wrote:
> > > >>
> > > >> > This is what I was looking for, but the DelegatingCollector
> 'finish'
> > > >> method
> > > >> > doesn't exist in 4.3.0 :( Can this be patched in and are there
> any
> > > >> other
> > > >> > PostFilter dependencies on 4.5?
> > > >> >
> > > >> > Thanks,
> > > >> > Peter
> > > >> >
> > > >> >
> > > >> > On Wed, Dec 11, 2013 at 3:16 PM, Joel Bernstein <
> joels...@gmail.com
> > >
> > > >> > wrote:
> > > >> >
> > > >> > > Here is one approach to use in a postfilter
> > > >> > >
> > > >> > > 1) In the collect() method call score for each doc. Use the
> scores
> > > to
> > > >> > > create your scaleInfo.
> > > >> > > 2) Keep a bitset of the hits and a priorityQueue of your top X
> > > >> ScoreDocs.
> > > >> > > 3) Don't delegate any documents to lower collectors in the
> > collect()
> > > >> > > method.
> > > >> > > 4) In the finish method create a score mapping (use the hppc
> > > >> > > IntFloatOpenHashMap) with your top X docIds pointing to their
> > score,
> > > >> > using
> > > >> > > the priorityQueue created in step 2. Then iterate the bitset
> (also
> > > >> > created
> > > >> > > in step 2) sending down each doc to the lower collectors,
> > retrieving
> > > >> and
> > > >> > > scaling the score from the score map. If the document is not in
> > the
> > > >> score
> > > >> > > map then send down 0.
> > > >> > >
> > > >> > > You'll have setup a dummy scorer to feed to lower collectors.
> The
> > > >> > > CollapsingQParserPlugin has an example of how to do this.
> > > >> > >
> > > >> > >
> > > >> > >
> > > >> > >
> > > >> > > On Wed, Dec 11, 2013 at 2:05 PM, Peter Keegan <
> > > peterlkee...@gmail.com
> > > >> > > >wrote:
> > > >> > >
> > > >> > > > Hi Joel,
> > > >> > > >
> > > >> > > > I thought about using a PostFilter, but the problem is that
> the
> > > >> 'scale'
> > > >> > > > function must be done after all matching docs have been scored
> > but
> > > >> > before
> > > >> > > > adding them to the PriorityQueue that sorts just the rows to
> be
> > > >> > returned.
> > > >> > > > Doing the 'scale' function wrapped in a 'query' is proving to
> be
> > > too
> > > >> > slow
> > > >> > > > when it visits every document in the index.
> > > >> > > >
> > > >> > > > In the Collector, I can see how to get the field values like
> > this:
> > > >> > > >
> > > >> > > >
> > > >> > >
> > > >> >
> > > >>
> > >
> >
> indexSearcher.getSchema().getField("field(myfield").getType().getValueSource(SchemaField,
> > > >> > > > QParser).getValues()
> > > >> > > >
> > > >> > > > But, 'getValueSource' needs a QParser, which isn't available.
> > > >> > > > And I can't create a QParser without a SolrQueryRequest, which
> > > isn't
> > > >> > > > available.
> > > >> > > >
> > > >> > > > Thanks,
> > > >> > > > Peter
> > > >> > > >
> > > >> > > >
> > > >> > > > On Wed, Dec 11, 2013 at 1:48 PM, Joel Bernstein <
> > > joels...@gmail.com
> > > >> >
> > > >> > > > wrote:
> > > >> > > >
> > > >> > > > > Peter,
> > > >> > > > >
> > > >> > > > > It sounds like you could achieve what you want to do in a
> > > >> PostFilter
> > > >> > > > rather
> > > >> > > > > then extending the TopDocsCollector. Is there a reason why a
> > > >> > PostFilter
> > > >> > > > > won't work for you?
> > > >> > > > >
> > > >> > > > > Joel
> > > >> > > > >
> > > >> > > > >
> > > >> > > > > On Tue, Dec 10, 2013 at 3:24 PM, Peter Keegan <
> > > >> > peterlkee...@gmail.com
> > > >> > > > > >wrote:
> > > >> > > > >
> > > >> > > > > > Quick question:
> > > >> > > > > > In the context of a custom collector, how does one get the
> > > >> values
> > > >> > of
> > > >> > > a
> > > >> > > > > > field of type 'ExternalFileField'?
> > > >> > > > > >
> > > >> > > > > > Thanks,
> > > >> > > > > > Peter
> > > >> > > > > >
> > > >> > > > > >
> > > >> > > > > > On Tue, Dec 10, 2013 at 1:18 PM, Peter Keegan <
> > > >> > > peterlkee...@gmail.com
> > > >> > > > > > >wrote:
> > > >> > > > > >
> > > >> > > > > > > Hi Joel,
> > > >> > > > > > >
> > > >> > > > > > > This is related to another thread on function query
> > > matching (
> > > >> > > > > > >
> > > >> > > > > >
> > > >> > > > >
> > > >> > > >
> > > >> > >
> > > >> >
> > > >>
> > >
> >
> http://lucene.472066.n3.nabble.com/Function-query-matching-td4099807.html#a4105513
> > > >> > > > > > ).
> > > >> > > > > > > The patch in SOLR-4465 will allow me to extend
> > > >> TopDocsCollector
> > > >> > and
> > > >> > > > > > perform
> > > >> > > > > > > the 'scale' function on only the documents matching the
> > main
> > > >> > dismax
> > > >> > > > > > query.
> > > >> > > > > > > As you mention, it is a slightly intrusive design and
> > > requires
> > > >> > > that I
> > > >> > > > > > > manage my own PriorityQueue (and a local duplicate of
> > > >> HitQueue),
> > > >> > > but
> > > >> > > > > > should
> > > >> > > > > > > work. I think a better design would hide the PQ from the
> > > >> plugin.
> > > >> > > > > > >
> > > >> > > > > > > Thanks,
> > > >> > > > > > > Peter
> > > >> > > > > > >
> > > >> > > > > > >
> > > >> > > > > > > On Sun, Dec 8, 2013 at 5:32 PM, Joel Bernstein <
> > > >> > joels...@gmail.com
> > > >> > > >
> > > >> > > > > > wrote:
> > > >> > > > > > >
> > > >> > > > > > >> Hi Peter,
> > > >> > > > > > >>
> > > >> > > > > > >> I've been meaning to revisit configurable ranking
> > > collectors,
> > > >> > but
> > > >> > > I
> > > >> > > > > > >> haven't
> > > >> > > > > > >> yet had a chance. It's on the shortlist of things I'd
> > like
> > > to
> > > >> > > tackle
> > > >> > > > > > >> though.
> > > >> > > > > > >>
> > > >> > > > > > >>
> > > >> > > > > > >>
> > > >> > > > > > >> On Fri, Dec 6, 2013 at 4:17 PM, Peter Keegan <
> > > >> > > > peterlkee...@gmail.com>
> > > >> > > > > > >> wrote:
> > > >> > > > > > >>
> > > >> > > > > > >> > I looked at SOLR-4465 and SOLR-5045, where it appears
> > > that
> > > >> > there
> > > >> > > > is
> > > >> > > > > a
> > > >> > > > > > >> goal
> > > >> > > > > > >> > to be able to do custom sorting and ranking in a
> > > >> PostFilter.
> > > >> > So
> > > >> > > > far,
> > > >> > > > > > it
> > > >> > > > > > >> > looks like only custom aggregation can be implemented
> > in
> > > >> > > > PostFilter
> > > >> > > > > > >> (5045).
> > > >> > > > > > >> > Custom sorting/ranking can be done in a pluggable
> > > collector
> > > >> > > > (4465),
> > > >> > > > > > but
> > > >> > > > > > >> > this patch is no longer in dev.
> > > >> > > > > > >> >
> > > >> > > > > > >> > Is there any other dev. being done on adding custom
> > > sorting
> > > >> > > (after
> > > >> > > > > > >> > collection) via a plugin?
> > > >> > > > > > >> >
> > > >> > > > > > >> > Thanks,
> > > >> > > > > > >> > Peter
> > > >> > > > > > >> >
> > > >> > > > > > >>
> > > >> > > > > > >>
> > > >> > > > > > >>
> > > >> > > > > > >> --
> > > >> > > > > > >> Joel Bernstein
> > > >> > > > > > >> Search Engineer at Heliosearch
> > > >> > > > > > >>
> > > >> > > > > > >
> > > >> > > > > > >
> > > >> > > > > >
> > > >> > > > >
> > > >> > > > >
> > > >> > > > >
> > > >> > > > > --
> > > >> > > > > Joel Bernstein
> > > >> > > > > Search Engineer at Heliosearch
> > > >> > > > >
> > > >> > > >
> > > >> > >
> > > >> > >
> > > >> > >
> > > >> > > --
> > > >> > > Joel Bernstein
> > > >> > > Search Engineer at Heliosearch
> > > >> > >
> > > >> >
> > > >>
> > > >>
> > > >>
> > > >> --
> > > >> Joel Bernstein
> > > >> Search Engineer at Heliosearch
> > > >>
> > > >
> > > >
> > >
> >
> >
> >
> > --
> > Joel Bernstein
> > Search Engineer at Heliosearch
> >
>
--
Joel Bernstein
Search Engineer at Heliosearch
