I have couple of interview questions. Can any one please through some lights on this.

1. What are the init parameters to improve the full tablespace in SQL QUERY?

2. I have table which has huge number of records. Let us say, table has 500 million records. My business logic is forcing me to scan the entire table. I am using PARALLEL hint to get better performance. How the parrellel process works internally? How multiple process works on the same table and join the results?? Since there is only one table and how multiple process hit the same table and join the result?