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https://issues.apache.org/jira/browse/LUCENE-10023?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17379129#comment-17379129
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Adrien Grand commented on LUCENE-10023:
---------------------------------------

bq. if there's interest in leveraging this from "other-than-Solr" (e.g., 
Elasticsearch, etc. ...

We had considered supporting something like that a few years ago before 
changing our minds. There were really only two use-cases for this, which were 
building tag clouds of analyzed tokens - which is a much less frequent need 
than doing the same over non-analyzed strings, e.g. tags - and performing 
analysis of significant terms. It didn't feel right to increase the API surface 
area of text fields with a new option to index doc values for a tiny minority 
of users so we decided against adding this option. We have since moved to term 
vectors instead for the few use-cases that need something like this, with a 
recommendation of only running such analysis on top hits.

> Multi-token post-analysis DocValues
> -----------------------------------
>
>                 Key: LUCENE-10023
>                 URL: https://issues.apache.org/jira/browse/LUCENE-10023
>             Project: Lucene - Core
>          Issue Type: Improvement
>          Components: core/index
>            Reporter: Michael Gibney
>            Priority: Major
>          Time Spent: 50m
>  Remaining Estimate: 0h
>
> The single-token case for post-analysis DocValues is accounted for by 
> {{Analyzer.normalize(...)}} (and formerly {{MultiTermAwareComponent}}); but 
> there are cases where it would be desirable to have post-analysis DocValues 
> based on multi-token fields.
> The main use cases that I can think of are variants of faceting/terms 
> aggregation. I understand that this could be viewed as "trappy" for the naive 
> "Moby Dick word cloud" case; but:
> # I think this can be supported fairly cleanly in Lucene
> # Explicit user configuration of this option would help prevent people 
> shooting themselves in the foot
> # The current situation is arguably "trappy" as well; it just offloads the 
> trappiness onto Lucene-external workarounds for systems/users that want to 
> support this kind of behavior
> # Integrating this functionality directly in Lucene would afford consistency 
> guarantees that present opportunities for future optimizations (e.g., shared 
> Terms dictionary between indexed terms and DocValues).
> This issue proposes adding support for multi-token post-analysis DocValues 
> directly to {{IndexingChain}}. The initial proposal involves extending the 
> API to include {{IndexableFieldType.tokenDocValuesType()}} (in addition to 
> existing {{IndexableFieldType.docValuesType()}}).



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