you are both right.
Block Cleanout can cause an ORA-1555, even in a read only
the tablespace has been read only "for a long enough period of
against it will realize that all updates to objects in that tablespace
committed, and will never try to reconstruct the table.
happens, I have never had an ORA-1555 on a table which is
during the query; I've had lots of them due to delayed block
This was my
first thought when I read the original post, however, as I read the
I think that
the errors are appearing after the tablespace has been read
If the time
Make tablespace read only
Error appear for a while
Then they never appear until the next iteration
cause is almost certainly delayed block cleanout. FWIW, I have
hours may not be enough time for everything to settle down.
As a test,
(if the OP is still reading, and my time sequence is spot on),
all statistics on all objects in the tablespace (not estimate,
compute). This will visit every block on all
tables and indexes (if any are
tablespace) and should clean out all the blocks.
Actually, you can get an ORA-1555 on an object in a read only
tablespace, believe it or not:
[mailto:email@example.com] On Behalf Of Justin
Sent: Friday, June 11, 2004 6:15 AM
Subject: RE: Tbs READ ONLY and Snapshot too
ORA-01555 indicates that Oracle was attempting to
reconstruct the state of a block and the earlier state was not available in
the undo segments. By definition, you cannot get an ORA-01555 error
when trying to access a read-only object.