Some applications require filtering documents by a large number of terms. It's often related to security filtering. Naively this is done this way:
And this ends up being a BooleanQuery. Users then wind up hitting BooleaQuery.maxClauseCount (sometimes in production, sadly) and they up it to a huge number to get the job done.
Solr should offer a QParser based on TermsFilter. I propose it be named "terms" (plural of term), and have a "separator" option defaulting to a space. When it's a space, the values also get trimmed, which wouldn't otherwise happen. The analysis logic should be the same as that for "term" QParser which is to call FieldType.readableToIndexed.