This post is older than a year. Consider some information might not be accurate anymore.
CLASSPATH exists; the driver is appended. For Windows:
SET ORACLE_JAR=C:\Data\lib\db\ojdbc6-11g.jar SET CLASSPATH="%CLASSPATH%;%ORACLE_JAR%" ECHO %CLASSPATH% "C:\Data\lib\db\ojdbc6-11g.jar"
export ORACLE_JAR=/opt/lib/db/ojdbc6-11g.jar export CLASSPATH="$ORACLE_JAR:$CLASSPATH" # check setting echo $CLASSPATH