enq tm contention on online shrinking
AlleTAug 14 2012 — edited Aug 16 2012Hi,
I am on 10.2.0.4. I can't clearly understand what's going on in this situation.
I have a table T with an index T_IDX.
Session 1: alter index T_IDX shrink space
Session 2: insert into T select * from ...
Session 3: update T set ....
When I execute these actions I see session 2 performing I/O while sessions 2 and 3 wait on enq - TM contention.
i understand that session 2 is blocked by session 1 as it has to access the newly inserted blocks of the index. But why the update is blocked? It does not access the newly inserted rows as they are not committed.
If I stop the shrinking the locks will disappear.
Any help appreciated
Regards