Is it possible to compute facets with "pattern trick"?

[aindlq]

Hi there!

I'm looking into qlever to see if it can replace blazegraph and wonder if it is possible to compute facets with "pattern trick" to avoid the issue with large intermediate results in plain SPARQL?

Let's say we have a predicate for which we want to generate all possible values together with count for a given constrain set of subjects.
In plain SPARQL it can be done with the following query:

SELECT ?value (COUNT(DISTINCT ?subject) AS ?count) WHERE {
  ?subject a crm:E22_Man-Made_Object .
  ?subject fr:Work_consists_of_Material ?value .
}
GROUP BY ?value
ORDER BY DESC (?count)

As an example you can see facet UI here - https://amara-west.researchspace.org/resource/rsp:ThinkingFrames?view=simple-search

I can see that something similar was asked in this issue - #985 and looks like the following PR is also somehow related #366. But from the discussion there I'm not sure if something like that is already possible.