[hibernate-dev] [HSearch] Facet drilldown

[Sanne Grinovero]

2011/3/14 Hardy Ferentschik <hibernate at ferentschik.de>:
> Thanks, great feedback as always.
>
>> the filtering idea is looking great.
>> I'm wondering how this affects performance, but I guess we can focus
>> on API and feature for now.
>
> Right. I am most interested in getting the API right atm.
> Do you think that filtering has a worse performance than executing a new
> query? Obviously we can wrap the FacetFilters in CachingWrapperFilter.

No I assume that filtering should be better, but I wonder if we can
skip both filtering and querying, it seems you already have collected
all what is needed. But I agree it's not a concern at this point, just
making notes for when we'll have time to explore this - if there's any
need.

>
> One thing I am still not sure about is my use of NumericRangeFilter for
> the numeric range facets. This requires that the faceted field is actually
> a @NumericField. Given the performance benefits of a numeric field, it just
> makes sense to use in your mapping, but should we cater for other cases as
> well?

I'd say this is fine. There are corner cases in which people want to
avoid NumericField,
but they are very rare and I guess the cases in which this coincides
with a range faceting need should be even less.

>
>> I'm a bit concerned on the result type of a faceting query, it seems
>> that even your own tests need a three-liner helper method to get to
>> the value you actually need.
>> What about trying to improve that, like from the current form:
>> List<Facet> facetList = query.getFacetResults().get( facetName
>> ).getFacets();
>> shorter:
>> List<Facet> facetList = query.getFacets( facetName );
>> WDYT?
>
> You are right. FacetResult does not contain much information. Once could
> even
> think about pushing the field name into Facet (even though it would be
> duplicated
> then in each Facet).

I guess it comes at a cost of a pointer, quite cheap.

>
> What you are loosing by query.getFacets( facetName ) is the ability to
> iterate over the
> enabled facets. At the very least you have to take care yourself of which
> facet names are set.
> In intermediate step would be to get rid of FacetResult, but keep returning
> a Map.
> So instead of Map<String, FacetResult> we have a Map<String, List<Facet>>.
> Or we go query.getFacets( facetName ), but also add a
>  query.getEnabledFacetNames()

In which case you do iterate per facets? I couldn't find examples, but
your mid-in suggestions seems fine.

Sanne

>
> --Hardy
>
>