There are some differences. StringField is indexed into the inverted index (postings) so you can do efficient filtering. You can also store in stored fields to retrieve.
FacetField does everything StringField does (filtering, storing (maybe?)), but in addition it stores data for faceting. I.e. you can compute facet counts or simple aggregations at search time. FacetField is also hierarchical: you can filter and facet by different points/levels of your hierarchy. Mike McCandless http://blog.mikemccandless.com On Fri, Oct 20, 2023 at 5:43 AM Michael Wechner <michael.wech...@wyona.com> wrote: > Hi > > I have found the following simple Facet Example > > > https://github.com/apache/lucene/blob/main/lucene/demo/src/java/org/apache/lucene/demo/facet/SimpleFacetsExample.java > > whereas for a simple categorization of documents I currently use > StringField, e.g. > > doc1.add(new StringField("category", "book")); > doc1.add(new StringField("category", "quantum_physics")); > doc1.add(new StringField("category", "Neumann")) > doc1.add(new StringField("category", "Wheeler")) > > doc2.add(new StringField("category", "magazine")); > doc2.add(new StringField("category", "astro_physics")); > > which works well, but would it be better to use Facets for this, e.g. > > doc1.add(new FacetField("media-type", "book")); > doc1.add(new FacetField("topic", "physics", "quantum"); > doc1.add(new FacetField("author", "Neumann"); > doc1.add(new FacetField("author", "Wheeler"); > > doc1.add(new FacetField("media-type", "magazine")); > doc1.add(new FacetField("topic", "physics", "astro"); > > ? > > IIUC the StringField approach is more general, whereas the FacetField > approach allows to do a more specific categorization / search. > Or do I misunderstand this? > > Thanks > > Michael > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > For additional commands, e-mail: java-user-h...@lucene.apache.org > >
