As you've observed, it is indeed possible to facet on fields with docValues=true, indexed=false; but in almost all cases you should probably set indexed=true. 1. for distributed facet count refinement, the "indexed" approach is used to look up counts by value; 2. assuming you're wanting to do something usual, e.g. allow users to apply filters based on facet counts, the filter application would use the "indexed" approach as well. Where indexed=false, if either filtering or distributed refinement is attempted, I'm not 100% sure what happens. It might fail, or lead to inconsistent results, or attempt to look up results via the equivalent of a "table scan" over docValues (I think the last of these is what actually happens, fwiw) ... but none of these options is likely desirable.
Michael On Mon, Oct 19, 2020 at 1:42 PM uyilmaz <uyil...@vivaldi.net.invalid> wrote: > > Thanks! This also contributed to my confusion: > > https://lucene.apache.org/solr/guide/8_4/faceting.html#field-value-faceting-parameters > > "If you want Solr to perform both analysis (for searching) and faceting on > the full literal strings, use the copyField directive in your Schema to > create two versions of the field: one Text and one String. Make sure both are > indexed="true"." > > On Mon, 19 Oct 2020 13:08:00 -0400 > Alexandre Rafalovitch <arafa...@gmail.com> wrote: > > > I think this is all explained quite well in the Ref Guide: > > https://lucene.apache.org/solr/guide/8_6/docvalues.html > > > > DocValues is a different way to index/store values. Faceting is a > > primary use case where docValues are better than what 'indexed=true' > > gives you. > > > > Regards, > > Alex. > > > > On Mon, 19 Oct 2020 at 12:51, uyilmaz <uyil...@vivaldi.net.invalid> wrote: > > > > > > > > > Hey all, > > > > > > From my little experiments, I see that (if I didn't make a stupid > > > mistake) we can facet on fields marked as both indexed and stored being > > > false: > > > > > > <field name="nonStorednonIndexedDocvalues" type="string" indexed="false" > > > stored="false" docValues="true"/> > > > > > > I'm suprised by this, I thought I would need to index it. Can you confirm > > > this? > > > > > > Regards > > > > > > -- > > > uyilmaz <uyil...@vivaldi.net> > > > -- > uyilmaz <uyil...@vivaldi.net>
