Getting started with the subject of SCJD.

Hi all,
I've read almost all essential topics in this forum but several questions regarding demands of this project are still in my unanswered folder:-)
1. Lock/Unlock idea. Should we implement dirty read? That means should we distinguish between reading lock and writing lock? I think if a client is gonna just read the data about available seats it shouldn't block others from doing the same query. But if a client is changing the data (just booking a seat in our case) it must prevent others from accessing to the same records.
2. According to the specification of the exam I see the following definition:
� To connect with your server, you should create a client program. This implementation should include a class that implements the same public methods as the suncertify.db.Data class... Does it mean that lock() and unlock() methods may not be implemented on the client side (because they�re not in the Data class)? I don't see any reason to expect from client side calling methods in a certain consistency. Although I've seen several posts here telling some guys did it. I suppose not to modify suncertify.db.db class but rather extend it and add locking machinery there. So the client will have only criteriaFind(String criteria) and book(int recNum) methods but the server in turn will call appropriate consistence of methods for locking, unlocking and gathering data from the DB.
Did I miss something or understand incorrectly?

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[This message has been edited by Roman Rytov (edited October 23, 2001).]

Hey guys!
Is my question too obvious or is it too stupid that no one has answered me yet?
Please give me your points.

Originally posted by Roman Rytov:
1. Lock/Unlock idea. Should we implement dirty read?

Read locks, or doing anything about dirty reads, is outside the scope of the project. For the FBN app there is no issue there anyway, since updates never cover more than one record - data is never in an inconsistent state.

Does [the requirement] mean that lock() and unlock() methods may not be implemented on the client side (because they�re not in the Data class)?

Aren't they? They were in my Data class back when I did the assignment, albeit empty. I think you can make a case for adding empty implementations of lock() and unlock() to Data.
- Peter

[This message has been edited by Peter den Haan (edited October 24, 2001).]