Table::Denormalized::ColumnRefiner - find columns that refine a query
$r->refinements QUERY, RESULTCOUNT
Returns the column refinements.
The (optional) result count is the number of rows in the result of the query. If this is unknown, it can be left out. A modified version of the query will then be run for the row count.
$r->implicit_columns QUERY, RESULTCOUNT
Returns the implicit columns (and their values).