issue 1:
D:oraclediag dbms race>expdp "/ as sysdba" schemas=JUSTIN dumpfile=JUSTIN_120803.dmp directory=datapumpdir
Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
ORA-31626: job does not exist
ORA-31650: timeout waiting for master process response
MOS常见的原因是
1 RAC不同节点试图同时使用expdp
2 sga不足，调整sga_target至少为1G
3 aq_tm_processes=0
解决方法：
但该数据库是单实例，且sga_target/sga_max_size=8g应该足够了，应该是第3种原因，果然aq_tm_processes设置为0，刚开始该为2，仍然抱错，接着改成10才成功。重新启动db,才能生效：
issue 2:
expdp导出遇到ORA-39064: 无法写入日志文件
expdp导出遇到ORA-39064: 无法写入日志文件
- . . 导出了 "USER_XXXX"."TAB_YYYY" 0 KB 0 行
- ORA-39064: 无法写入日志文件
- ORA-29285: 文件写入错误
经过搜索mos，有如下的文章给出了解决方案：
Error ORA-39064 Might Be Encountered By DataPump Export (EXPDP) When
NLS_LANG Is Different From Database Character Set (Doc ID 1321034.1)
在该方案中给出的解决方案是：Please set the character set in environment variable NLS_LANG to database character set.
方法如下：
set nls_lang=
env|grep LANG
LANG=en_US
|
Table 4 NLS_LANG Parameter Values for Linux Locales LanguageLocale IDNLS_LANG
|