I can only halfway connect to oracle

Gurus...

If I set up my project to use SQLite (so it can come up) and attempt to
connect to oracle via:

oracle_connect = $application_properties[$connect_string]
oracle_conn = OCI8.new(oracle_id, oracle_password, oracle_connect)

where oracle_connect equals '//bobs.big.boy.gov:1521/D09' (with or w/o
the introductory //) my rails app connect to the oracle database just
fine.

If I convert my database.yml file to point to oracle however with the
following config:

development:
  adapter: oracle
  database: pst_development
  password:
  host: bobs.big.boy.gov:1521/D09 #with or w/o the introductory //
  username: foo
  password: foo

When I try and run my initial migration to get setup I see the following
error:

rake aborted!
ORA-12154: TNS:could not resolve the connect identifier specified

Help please!