Oracle Database Discussions

Please answer these questions from a DBA point of view.

1.What happens when we kill smon,
2.What happen when we kill pmon
3.What is a fractured block and how to fix it
4.What is a corrupted block and how to fix it
5.What are the oracle threads which start when we start the database.
6.How do we check a index is working properly and how do we decide a particular index has to rebuilt.
7. What steps do we take if we receive a call that performance has gone
down as a dba.
8.What possible errors can we able to see in a alert file.
9.If suddenly performance goes down what steps to be taken without using
alert file.
10.If users are not able to connect database or database is down what preliminary steps are to be taken.
11.What does oracle do when we take hot backup where actually modified
blocks are written?
12. On what basis should RAM be determined for a 50gb database.
13.Can we connect a database using listener instead of tnsnames.
14.Normally what are the jobs a DBA has to do on a daily basis?
15. Can we create a physical standby database using hot backup.
16.Is there a limit for concurrent user connections in Oracle.
17.Can we increase user connections by using LISTENER FILE
18.If we wish to write a query how do we make it a efficient query and how to make
execution plans for that query.


Yachendra