Hi Shai,
i)Hope, when opening SortedSetDocValuesReaderState , we are
calculating ordinals( this will be used to calculate facet count ) for doc
values field and this only made the state instance somewhat costly.
Am I right or any other reason behind that?
ii) During indexing, we are providing facet ordinals in each doc
and I think it will be useful in search side, to calculate facet counts
only for matching docs. otherwise, it carries any other benefits?
iii) Is SortedSetDocValuesReaderState thread-safe (ie) multiple
threads can call this method concurrently?
Kindly post your suggestions.
Thanks,
Chitra
On Thu, Nov 10, 2016 at 4:34 PM, Shai Erera <ser...@gmail.com> wrote:
> Hi
>
> The reason IMO is historic - ES and Solr had faceting solutions before
> Lucene had it. There were discussions in the past about using the Lucene
> faceting module in Solr (can't tell for ES) but, sadly, I can't say I see
> it happening at this point.
>
> Regarding your other question, IMO the Lucene faceting engine, in terms of
> performance and customizability, is on par with Solr/ES. However, it lacks
> distributed faceting support and aggregations. Since many people use
> Solr/ES and not Lucene directly, the Solr/ES faceting module continues to
> advance separately from the Lucene one.
>
> Enhancing Lucene facets with aggregations and even distributed faceting
> capabilities is mostly a matter of time and priorities. If you're
> interested in it, I'd be willing to collaborate with you on that as much as
> I can!
>
> And I'd still hope that this work finds its way into Solr/ES, as I think
> it's silly to have that many number of faceting implementations, where they
> all rely on the same low-level data structure - Lucene!
>
> Shai
>
>
> On Thu, Nov 10, 2016 at 12:32 PM Kumaran Ramasubramanian <
> kums....@gmail.com>
> wrote:
>
> > Hi All,
> > We all know that Lucene supports faceting by providing
> > Taxonomy(Separate index and hierarchical facets) and
> > SortedSetDocValuesFacetField ( flat facets and no sidecar index).
> >
> > Then why did solr and elastic search go for its own implementation
> ?
> > ( that is, solr uses block join & elasticsearch uses aggregations ) Is
> > there any limitations in lucene's implementation ?
> >
> >
> > --
> > Kumaran R
> >
>
