The documentation on the Flashback Retention Target in 11.2 and 12.1 states that this parameter specifies an upper limit on how far the database may be flashed back.
Quick and Rough Notes : Undo and RedoUndo is where Oracle logs how to reverse a transaction (one or more DMLs in a transaction)Redo is where Oracle logs how to replay a transactionUndo and Redo are written to as the transaction proceeds, not merely at the end of the transaction(imagine a transaction that consists of 1million single-row inserts, each distinct insert is written to undo and redo) Undo segmentsOracle dynamically creates and drops Undo segments depending on transaction volumeAn undo segment consists of multiple extents.
The 12c AWR Report section on Segment Statistics now reports both Obj# (OBJECT_ID) and DataObj# (DATA_OBJECT_ID).
The DIRECT parameter for SQLLoader Command-Line enables Direct Path Load which uses a Direct Path API instead of a regular INSERT statement to load data into the target table.
Here are some extracts from an 126.96.36.199 AWR Report I ran a simulated workload on this server for about 40minutes and generated this report.