It’s possible to have also two different version listeners (the 9 and 10 version) running, by settting different ORACLE_HOME’s and PATH’s, and starting the different listeners. I like to have 1 listener – as long as this can be maintained regarding incompatibility and bugs etc – therefore my latest listener version is leading (version 10g). Set your ORACLE_HOME accordingly. My 10g Oracle home is placed in directory/oracle/rdb10g/ and my TNS_ADMIN directory is set to directory /oracle/network/admin.
C:\> export ORACLE_HOME=/oracle/rdb10g C:\> export TNS_ADMIN=/oracle/network/admin C:\> export PATH=$ORACLE_HOME/bin:$PATH