I'm trying to understand the difference between something like
fq={!cache=false}(tag:* -tag:email) which is very slow compared to
fq={!cache=false}(*:* -tag:email) on Solr 7.7.1.I believe in the case of `tag:*` Solr spends some effort to gather all of the documents that have a value for `tag` and then removes those with `-tag:email` while in the `*:*` Solr simply uses the document set as-is and then remove those with `-tag:email` (*and I believe Erick mentioned there were special optimizations for `*:*`*)?
