i have some questions please answer its argent:-
1.describe where dbms is not better option & file base system is better.
2.how 2-phase locking differ from 2-phase commit.
3.describe all ACID propertis?
4.compare ms access and oracle?
5.what is fragmentation and its types?
6.how centralized dbms differ from distributed dbms?is oracle we are having variety of version oracle 8,oracle 9 etc what does the associated number means and same as oracle 8i,oracle 9i..... what does i.. means?

Your question is too much theoritical to explain here. It is beyond the scope of this discussion . Please go through so good book or manual or you can easily find all that by little web-searching.