SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function count (children 1)
     ExpressionList
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier distr (alias l)
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier distr (alias r)
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier l.a
        Identifier r.a
