Faceting: Taxonomy index Vs SortedSetDocValues

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Faceting: Taxonomy index Vs SortedSetDocValues

Chitra R
Hi,

Issues(LUCENE-4795):  Add FacetsCollector based on SortedSetDocValues

https://issues.apache.org/jira/browse/LUCENE-4795


i) In the above discussion, mentioned that there is no need to maintain
sidecar index to collect facets & its count (FacetsCollector) and even we
can achieve it in flat index using SortedSetDocValues...  Then what is the
main benefits of using Sidecar or Taxonomy index?

ii)And i tried to achieve multilevel (hierarchical) categorization using
SortedSetDocValues and got it simply by changing the query  and opening the
IndexReader for each level of query using SortedSetDocValuesReaderState..


And i know, in SortedSetDocValuesFacetField
>
>
>    - Faceting is a bit slower  (~25%), and there is added cost on
>    every IndexReader open to create a new SortedSetDocValuesReaderState.
>
>
>    - does not support hierarchical facets
>
>


1. what are the functionalities we will be missing when we use
SortedSetDocValues for faceting? what is hierarchical facets? what can we
achieve using hierarchical facets?


2. Except faster faceting and supporting hierarchical facets, is there any
benefit of using taxonomy index over docvalues field for faceting?


Any ideas/help/recommendations greatly appreciated..


Regards,
Chitra
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Re: Faceting: Taxonomy index Vs SortedSetDocValues

Chitra R
Hi,

          Kindly post your suggestions..

Chitra

On Mon, Sep 26, 2016 at 3:48 PM, Chitra R <[hidden email]> wrote:

> Hi,
>
> Issues(LUCENE-4795):  Add FacetsCollector based on SortedSetDocValues
>
> https://issues.apache.org/jira/browse/LUCENE-4795
>
>
> i) In the above discussion, mentioned that there is no need to maintain
> sidecar index to collect facets & its count (FacetsCollector) and even we
> can achieve it in flat index using SortedSetDocValues...  Then what is the
> main benefits of using Sidecar or Taxonomy index?
>
> ii)And i tried to achieve multilevel (hierarchical) categorization using
> SortedSetDocValues and got it simply by changing the query  and opening the
> IndexReader for each level of query using SortedSetDocValuesReaderState..
>
>
> And i know, in SortedSetDocValuesFacetField
>>
>>
>>    - Faceting is a bit slower  (~25%), and there is added cost on
>>    every IndexReader open to create a new SortedSetDocValuesReaderState.
>>
>>
>>    - does not support hierarchical facets
>>
>>
>
>
> 1. what are the functionalities we will be missing when we use
> SortedSetDocValues for faceting? what is hierarchical facets? what can we
> achieve using hierarchical facets?
>
>
> 2. Except faster faceting and supporting hierarchical facets, is there any
> benefit of using taxonomy index over docvalues field for faceting?
>
>
> Any ideas/help/recommendations greatly appreciated..
>
>
> Regards,
> Chitra
>
>
>
>
>
>
>