If nothing, but for information, I would try zodbconvert with the same source FileStorage against a stock PostgreSQL (see below) with really simple tuning for comparison's sake?
IMHO, you should post to the ZODB Google group/list, and include your storage configuration options from your zope.conf and possibly describing how your Oracle installation is set up.
If you do decide to try PostgreSQL to compare performance for informational purposes, here are some pointers:
Here is some simple postgresql.conf tuning from a modest config used in production with PostgreSQL 9.3 and RelStorage 1.6.
To use PostgreSQL, you only need a running server, a connection over TCP or domain socket, and running something similar to
$ psql template1 (insert user and port-specific bits as needed, per whatever is allowed in your pg_hba.conf) with a query like
CREATE USER admin WITH PASSWORD "bananas"; CREATE DATABASE zodb OWNER admin and a dsn in your relstorage config (zope.conf) pointing to the database 'zodb'.
If this convert runs fine in PostgreSQL, then you at least know there is definitely something up specific to Oracle (likely server config, much less likely the client adapter implementation in RelStorage).