per rails docs, oracle is supported but the rails ebuild only supports mysql/postgresql.
I dunno what you're talking about. The ebuild supports any db you want. If you want oracle, emerge it. Rails will work just fine with it.
Note that this requires the ruby-oci8 gem which isn't in portage. This is because I have no way to test it (since I'm not an oracle guy). If you need it, you probably need to talk to the people who maintain the rest of the oracle stuff in Gentoo.
OK. It looks like you are right that this may be more of a general ruby/oracle thing than anything to do with rails. My bad, the useflags for mysql/postgres/sqllite for rails threw me off. Anyhow, I have created a draft version of a ruby-oci8 ebuild and will test it later today. It makes it through repoman scan and seems to install correctly.
ok, if it works for you feel free to commit it and useflag rails for oracle if so desired.