It is a bit late but I had decent excuses like post upgrade problems (as usual on a system which wasnt tested properly when it was test db )
1- Why not to trust ASH.TIME_WAITED ?
Vitaliy Mogilevskiy- Making sense of ASH TIME_WAITED Units
2- Restrictions when using union all with Fast refreshable materialized views
3- Reasons of big SYSTEM tablespaces
Martin Widlake- Why is my SYSTEM Tablespace so Big?
Marcin Przepiorowski- andLinux and Oracle
5- How does Oracle fast refresh materialized views containing only joins of master tables
Alberto Dell’Era- fast refresh of join-only materialized views -algorithm summary
Martin Decker- Multipathing Configuration issue waiting to happen
8- Library Cache Pin wait caused by PL/SQL compalition
Kubilay Kara – Library Cache Pin Waits during PL/SQL compilation
9- Why export import is not reliable for detacting corrupt data blocks.
Jared Still- Detecting Corrupt Data Blocks
11- ORA-4031 when there is plenty of free space in SGA.
Riyaj Shamsudeen- ORA-4031 and Shared Pool Duration