Toad 引发的ORA-00600 17281错误

在客户的数据库环境中，多次发现ORA-600 17281错误：

ORA-00600: internal error code, arguments: [17281], [1001], [0x7000000F8300F20], [], [], [], [], []
ORA-01001: invalid cursor

17281的官方解释是：Error closing all cursors for an instantiation

引发的SQL是：

declare
  cursor NlsParamsCursor is
    SELECT * FROM nls_session_parameters;
begin
  SELECT Nvl(Lengthb(Chr(65536)), Nvl(Lengthb(Chr(65536)), 1))
    INTO :CharLength
    FROM dual;
  for NlsRecord in NlsParamsCursor loop
    if NlsRecord.parameter = 'NLS_DATE_LANGUAGE' then
      :NlsDateLanguage := NlsRecord.value;
    elsif NlsRecord.parameter = 'NLS_DATE_FORMAT' then
      :NlsDateFormat := NlsRecord.value;
    elsif NlsRecord.parameter = 'NLS_NUMERIC_CHARACTERS' then
      :NlsNumericCharacters := NlsRecord.value;
    elsif NlsRecord.parameter = 'NLS_TIMESTAMP_FORMAT' then
      :NlsTimeStampFormat := NlsRecord.value;
    elsif NlsRecord.parameter = 'NLS_TIMESTAMP_TZ_FORMAT' then
      :NlsTimeStampTZFormat := NlsRecord.value;
    end if;
  end loop;
end;

连接的客户端及Toad.exe可以从进程堆栈中得到：

    O/S info: user: Administrator, term: Wang, ospid: 3828:3732, machine: WORKGROUP\Wang
              program: TOAD.exe
    application name: TOAD.exe, hash value=0

这个错误出现在进程关闭游标时，是Metalink上标记的已知Bug，没有数据损失，可以忽略。