Unique entities based on field value

[yrodiere]

@fivearise

I’m using an n-gram filter to add a suggestions/autocomplete feature

This is probably not the right way to do it. Maybe look into that instead:

• Elasticsearch: Hibernate Search 6 suggesters + completion type
• Lucene (old but maybe still a bit relevant): [HSEARCH-1823] - Hibernate JIRA

@mbekhta

I don’t think there is a select distinct field from ... alternative in full-text search.

There is not in Hibernate Search at the moment, but there could be in the future: [HSEARCH-868] - Hibernate JIRA
If you use Elasticsearch, you can probably leverage the relevant feature through the Elasticsearch extension in Hibernate Search, but that involves dealing with JSON.

@mbekhta

If you just need to get the unique values of a single field, you could try using the terms aggregation: Hibernate Search 7.1.1.Final: Reference Documentation :

.aggregation( countsByGenreKey, f -> f.terms()
                .field( "field", String.class )
                .maxTermCount( 5 ) )

But then, I don’t think that that would be a good solution…

It’s a good solution if:

• the field is a keyword field; aggregations are not available on full-text fields.
• the orderings available in terms aggregations are what you’re after when you say “first five”.

Somehow I doubt it.