Because it dependes on an external library, the oracle module is not compiled and installed by default. You can use one of the next options.
- edit the "Makefile" and remove "db_oracle" from "excluded_modules" list. Then follow the standard procedure to install Kamailio: "make all; make install".
- from command line use: 'make all include_modules="db_oracle"; make install include_modules="db_oracle"'.
But
"db_oracle: requires non-free Oracle client SDK" (http://lists.sip-router.org/pipermail/sr-dev/2013-October/021803.html)
-- Best regards, Konstantin Khatskevich