dump   next_address   pos_undo_logs   pos_undo_page_header   pos_undo_segment_header   prev_address   size_undo_page_header   size_undo_segment_header   undo_log   undo_page_header   undo_segment_header  

UNDO_PAGE_TYPES	=	{ 1 => :insert, 2 => :update, }
UNDO_SEGMENT_STATES	=	{ 1 => :active, 2 => :cached, 3 => :to_free, 4 => :to_purge, 5 => :prepared, }