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Logical Backups:- ================= Logical backup can be considered as an alternate backup solution but not as main stream backup solution Useful in the case of databae upgration and database migrations Logical backups are platform independent It is useful in the case of data reorganisation Useful incase of moving objects from one schema to another schema Logical backups generate dump files and log files and we cannot edit dump files otherwise it will be corrupted Dump files contains meta data as well as business data we can take incremental bacups using logical backups and dump files cannot be imported using impdp utility Export can be done in 2 ways coventional path and direct path In conventional path it uses sql statement to bring the data from disk  to buffer cache and then it is evaluated to and traferred to export client which writes data to dump file In direct path , it will directly reads data from disk into export session of PGA and then transfers to expo...

Oracle memory architecture is divided in following memory structure:- System Global Area (SGA):- This is a large, shared memory segment that virtually all Oracle processes will access at one point or another. Process Global Area (PGA): This is memory that is private to a single process or thread; it is not accessible from other processes/threads. User Global Area (UGA): This is memory associated with your session. It is located either in the SGA or the PGA, depending whether you are connected to the database using a shared server (it will be in the SGA), or a dedicated server (it will be in the PGA). PGA is the memory reserved for each user process connecting to an Oracle Database and is allocated when a process is created and deallocated when a process is terminated. Contents of PGA:- Private SQL Area: Contains data such as bind information and run-time memory structures. It contains Persistent Area which contains bind information and is freed only when the curs...