Resolution:
The privileges required for database administrator user when creating an Adminstrator domain using a database repository on Oracle database are as follows:

grant create procedure,create sequence,create trigger,create type,create view,create session,create table to <admin_db_user>

We also recommend giving CONNECT and RESOURCE roles to the DB user which will be used for the Administration domain. 

In Oracle 10g, CONNECT role has CREATE SESSION and RESOURCE has CREATE CLUSTER, CREATE INDEXTYPE, CREATE OPERATOR, CREATE PROCEDURE, CREATE SEQUENCE, CREATE TABLE, CREATE TRIGGER and CREATE TYPE.

In essence, the user needs to have permissions be able to create database objects.

After the domain creation, the DB user privileges can not be reduced as new database objects may be created dependent upon the actions taken with the domain, for example setting a password policy or adding plug-ins or servers.

Please contact TIBCO support should you have further questions.