All process lasted for 6 weeks.
First they start with a maximum half of hour HR on phone interview where they ask you to rate yourself on different abilities ( e.g OS, database, scripting), also ask you to speak some English , of course if this is not your native language.
Last part of the phone interview is what is the minimum salary you will come to Oracle and what is the salary that will really motivate you. This is a very important phase because if you ask for too much they will stop the interview process and you will not pass to the next phase. You will get a positive answer after maximum 1 week.
First there was an interview with the manager, to know you better and to describe your previous working experience and after this a technical test that covered Linux/Unix and networking, not troubleshooting more theoretical( basic commands on Linux, and subneting, OSI stack ).
If everything is ok you will get an unofficial answer in maximum 1 week, but in 90% of the cases this means you will be accepted.
After this you will need to have patience, because the official job offer will come in minimum 3-4 weeks.