Implementing scheme/port(?) for Oracle DB in REN-C

Say I want to connect to an Oracle database.
On rebol sdk (see http://rebol.com/docs/database.html ) it says there is an Oracle scheme for R2 (but this is not yet available and it is not in R3/REN-C

Say I want to connect to the database that is named DBTEST and is on address i1.i2.i3.i4 using port 9999
The user (or schema for oracle) is RESU and password is SECRET.

Now how to create the scheme for Oracle in REN-C and how can can we create and use the connection to this DB?

The Oracle database connector for R2 was available to Rebol command users.
If you want the same in Renc, you're going to have to write it.
Otherwise use ODBC, which is what I did to connect to DB2.

Command should become freely available according to the latest 'rumours', though it could take some time.

So what exactly should be written to create such a thing?

Maybe it's just a protocol written on top of TCP/IP

See https://docs.oracle.com/cd/E11882_01/network.112/e41945/layers.htm#NETAG1510

I don't think Command is going to help as it will be closed source. Though I guess you could try and reverse engineer it if indeed it is using tcp/ip though it may be encrypted.

Thank you for the link Graham.
Agreed, Command will be available as closed source. Perhaps it uses the OCI interface. I'll dive into that for now.
Other suggestions are always welcome.