replication,security,logshipping,performance interview questions

Answer the following: it may helpful to newbies who wants their career as a dba
Sql dba freqently asked questions in interviews:
what are the dbroles,server roles
if user wants to update data in a db what dbroles I need to assign to ?
how I can give permissions to user on only one table in a db ?
what are the agents involved in merge replication?
what's the differance between transactional,merge replication? which one suits when>
what's if log reader is not working in any replication steup?
what are the differant issues face in your environment on replication(any errors/issues in replication) and how do you fix it?
what is the purpose of logshipping?
what are the endpoints in logshipping ?what r the port numbers for logshipping?
what are the logshipping frequent issues you have faced?
what are the index types and when you go for cluster index and non cluster index?
what is fillfactor?