Job environment

Don't make any assumptions about the environment your job runs in. Oracle has made lots of changes with regards to the environment the job gets when it is launched outside the database. In 9i, there is a Java method that enables us to start a job on the operating system that has lots of information in the environment. This environment got poorer with each upgrade. In earlier releases, ORACLE_HOME, PATH, and ORACLE_SID were defined and PWD was in $ORACLE_HOME/dbs. In 10g, these three variables disappeared. In 11gR1, the current directory of processes scheduled (using the remote external job agent), is the current directory at the time the agent started. So, you should not rely on any variable in the environment.

Before you start using external jobs, think about how the job should define its own environment. Don't forget about the ulimits, they also tend to change between releases. Even something as simple as a change in the stack size (limit -s) can have surprising consequences...