I am a beginner to .net cf and sql server ce, currently trying hard to complete my project which is a student attendance taking app using pda. And while searching for useful and understandable information, i am confused with the wide variety of choices that we can opt in developing the app.

i need some advice on the following subjects :

1) I've proposed a disconnected environment for my project where i'll get the data from central storage (SQL Server 2000) and sync it to PDA (in XML file) to be used as local data storage. When the information is updated, it will be pushed back to SQL Server. I think that this works OK in a limited connection environment, but it will violate the real time data access criteria of mobile computing. Can anybody tell me whether this decision is appropriate or not?

2) type of database that i should use when deal with pocket pc application. As shown in this article, SQL Server CE 2.0 was used and i really think it is cool. But i am weighing the benefits of using xml textfiles as my local data storage at the same time. Could anybody help me to justify, which one is better? in terms of ease of development, resource consumption - which would be more lightweight (on the pda), which is more preferable. I knew one of the consideration point would be the size of data that we want to parse, and it is not advisable to use xml if the qty of data is too big. When we say qty data is not too big, how do we actually measure whether it is big or small? what is the size that is considered as big and vice versa?

2) How to pull data from SQL Server 2000 to xml file to be used as local storage( in a disconnected environment) and update the data before pushing it back to SQL Server 2000?

Need feedback urgently.. Any helps and advises given will be greatly appreciated. Thank you