我同时unload好几张表，就会报 264: Could not write to a temporary file. 的错误，这是为什么啊，又没有对数据库进行写数据，而且用来存放卸出来文件的目录也足够大；我用onstat -d 看了，各dbspace的free空间也有很多啊
------解决方案--------------------
-264 Could not write to a temporary file.
The database server created a temporary file in the directory that the
DBTEMP environment variable (or /tmp by default on UNIX systems)
specifies, but it encountered an error when it tried to write data into
the file. To determine the cause of this error, check the accompanying ISAM
error code and look for operating-system error messages that might give
more invormation. Possible causes include: hardware failure, a full
disk, or, if PDQ is enabled, insufficient shared memory.
------解决方案--------------------
unload之前，export DBTEMP=/aaa
aaa是文件系统，需要Informix可以读写，并且有足够的空间。