SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Asterisk
   TablesInSelectQuery (children 3)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier tab
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier mem
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier k1
        Identifier mem.k
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier mem2
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier k2
        Identifier mem2.k
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier tab.v
