Oracle Database Undo Segment Operation Concept

Oracle Database Undo Segment Operation Concept

• 1.
  Extent  1 Extent  2 Tx1 Tx2 Tx3 undo  segment  1 ext1 ext2
• 2.
  Extent  1 Extent  2 Tx1 Tx2 Tx3 undo  segment  1 Tx4 Tx5 Tx6 ext1 ext2
• 3.
  Extent  1 Extent  2 Tx1 Tx2 Tx3 undo  segment  1 Tx4 Tx5 Tx6 Tx7 ext1 ext2
• 4.
  Extent  1 Extent  2 Tx1 Tx2 Tx3 undo  segment  1 Tx4 Tx5 Tx6 Tx7 Extent  3 ext1 ext2 ext3 Allocate     New  Extent Extent  1  is  ACTIVE/INACTIVE  extent
• 5.
  Extent  1 Extent  2 Tx1 Tx2 Tx3 undo  segment  1 Tx4 Tx5 Tx6 Tx7 ext1 ext2 Extent  1  is  EXPIRED  extent
• 6.
  Extent  1 Extent  2 undo  segment  1 Tx5 Tx6 Tx7 ext1 ext2