Explain EXPLAIN (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)
    ExpressionList (children 1)
     Asterisk
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier visits_order_dst
    Function equals (children 1)
     ExpressionList (children 2)
      Identifier user_name
      Literal \'another_user2\'
