When I have checked OTHER column in PLAN TABLE it is quite obvious what
is happening. The good plan is sending two complicated joins to be
processed in Teradata, but the bad one is sending instead of it four
queries of everything in a table with no where conditions, so it is
fetching all data and then is dealing with them in Oracle. Therefore it
is clear WHAT went wrong, but I still do not know WHY.
As I already wrote the session modifiable parameters regarding CBO are
exactly the same, I have checked this by comparing side by side the
event 10053 output. There is definitely no RLS used, because it is not
supported in distributed environments and we're all accessing database
using the same user so there couldn't be a difference in synonyms
and/or links.
--
Dusan Bolek
Received on Thu Feb 02 2006 - 10:15:52 CST
