Explain EXPLAIN PIPELINE (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 4)
    ExpressionList (children 4)
     Identifier fact_1_id
     Identifier fact_2_id
     Identifier fact_3_id
     Function SUM (alias sales_value) (children 1)
      ExpressionList (children 1)
       Identifier sales_value
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier grouping_sets
    ExpressionList (children 2)
     ExpressionList (children 2)
      Identifier fact_1_id
      Identifier fact_2_id
     ExpressionList (children 2)
      Identifier fact_1_id
      Identifier fact_3_id
    ExpressionList (children 3)
     OrderByElement (children 1)
      Identifier fact_1_id
     OrderByElement (children 1)
      Identifier fact_2_id
     OrderByElement (children 1)
      Identifier fact_3_id
