[Idrees]

I've a question. First time in my life it happened that I hired as a project manager in a medical company. Its seems that the project is very big. It'll involve tables of customers, medicines, staff and many other things. First I've to make a database. It seems that the project is very huge as the database has to be established in one center and it'll be accessed remotely. The doctor who hired me wants me to complete the whole application in just 15 days. I think it'll take 3 months to understand, analyze and design the system, but I am not sure about the time. So following are my questions.

1- How can I exactly estimate the time of analysis, design and development?

2- I've very little experience of database and I only know MS-Access till now. So currently I want to make the database in MS-Access. In future I'll migrate it into MS-SQL or MySQL.
So is this a good idea?

3- Is MySql as easy as MS-Sql? How can I judge weather I should work in MySql or MS-Sql or Oracle?