a0b4b3a0_great_grandson_of_Husnu_Sensoy__Classical_Optimistic_Locking
[0] Mostly suitable for [Pessimistic Locking] 2-tier architecture [Description] Since in 3-tier architecture the thread in the application server side is always subject to change, you need to store database connection somewhere in the application server(session beans or so), which may be very costly. But for applications communicating directly with database have no such need. You may open a single connection and perform all your transactions over a single connection. [Classical Optimistic Locking] 
3-tier architecture
H a r d e r
M o r e e x p e n s i v e
U s u a l l y m o r e c o m p l e x
N o
3 - t i e r a r c h i t e c t u r e
L o w e r
Y e s
A Locking Mechanism in Oracle 10g for Web Applications | The great grandson of Husnu Sensoy
Classical Optimistic Locking