Hi You can check the demo code here: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_8/lucene/demo/src/java/org/apache/lucene/demo/facet/. This code is updated with each release, so you always get a working code examples, even when the API changes.
If you don't mind managing the sidecar index, which I agree isn't such a big deal, then yes - the taxonomy index currently performs the fastest. I plan to explore porting the taxonomy-based approach from BinaryDocValues to the new SortedNumericDocValues (coming out in 4.9) since it might perform even faster. I didn't quite get the marker/flag facet. Can you give an example? For instance, if you can model that as a NumericDocValuesField added to documents (w/ the different markers/flags translated to numbers), then you can use Lucene's updatable numeric DocValues and write a custom Facets to aggregate on that NumericDocValues field. Shai On Fri, Jun 13, 2014 at 11:48 AM, Sandeep Khanzode < sandeep_khanz...@yahoo.com.invalid> wrote: > Hi, > > I am evaluating Lucene Facets for a project. Since there is a lot of > change in 4.7.2 for Facets, I am relying on UTs for reference. Please let > me know if there are other sources of information. > > I have a couple of questions: > > 1.] All categories in my application are flat, not hierarchical. But, it > seems from a few sources, that even that notwithstanding, you would want to > use a Taxonomy based index for performance reasons. It is faster but uses > more RAM. Or is the deterrent to use it is the fact that it is a separate > data structure. If one could do with the life-cycle management of the extra > index, should we go ahead with the taxonomy index for better performance > across tens of millions of documents? > > Another note to add is that I do not see a scenario wherein I would want > to re-index my collection over and over again or, in other words, the > changes would be spread over time. > > 2.] I need a type of dynamic facet that allows me to add a flag or marker > to the document at runtime since it will change/update every time a user > modifies or adds to the list of markers. Is this possible to do with the > current implementation? Since I believe, that currently all faceting is > done at indexing time. > > > ----------------------- > Thanks n Regards, > Sandeep Ramesh Khanzode
