EXP-00056: ORACLE error 600 encountered
ORA-00600: internal error code, arguments: [unable to load XDB library]
EXP-00000: Export terminated unsuccessfull

操作系统aix5L，oracle 版本10.2，导出的时候碰到这个错误，查询metalink，解决办法如下

1. Stop the database and stop the listener.

2. Set LD_LIBRARY_PATH so the first directory referenced is $ORACLE_HOME/lib
Example (replace $ORACLE_HOME with the full path of the Oracle home directory):

csh:$ setenv LD_LIBRARY_PATH=$ORACLE_HOME/lib
$ setenv LIBPATH=$ORACLE_HOME/lib

ksh:$ export LD_LIBRARY_PATH=$ORACLE_HOME/lib
$ export LIBPATH=$ORACLE_HOME/lib

For Oracle9i and Oracle10g on AIX: set environment variable LIBPATH and afterwards, run /usr/sbin/slibclean as root
For Oracle9i and Oracle10g on HP-UX, Linux, Solaris, and Tru64: set environment variable LD_LIBRARY_PATH

3. Re-start the database and the listener.

4. Re-run the export.