RE: ORA-01555 seems bogus
Date: Mon, 8 Feb 2010 09:42:03 -0800 (PST)
I agree that the overall culprit is often exactly what you have detailed below, but I think it is important to see that what you *think* is being used by your statement might be very different in reality when executed in whole- as part of that one procedure, etc... I think starting with undo is perfectly acceptable to see what the database has allocated towards the process, then proceed back, into the statement(s) in question to see where the logic is causing the issue or what other processes might be hampering the one that's been identified as the problem... :)
"Go away before I replace you with a very small and efficient shell script..."
- On Mon, 2/8/10, Goulet, Richard <Richard.Goulet_at_parexel.com> wrote:
From: Goulet, Richard <Richard.Goulet_at_parexel.com>
Subject: RE: ORA-01555 seems bogus
To: Dave.Herring_at_acxiom.com, oracle-l_at_freelists.org Date: Monday, February 8, 2010, 8:05 AM
An ORA-01555 is never bogus, but very misleading as you've found out. OK, so the query in question is part of a package. Is the package called from some application that's doing a "commit across a cursor", or is the package doing it internally? Lots of places to look and undo is the very last.
Senior Oracle DBA/NA Team Lead
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Herring Dave - dherri Sent: Saturday, February 06, 2010 10:10 PM To: oracle-l_at_freelists.org
Subject: ORA-01555 seems bogus
Folks, I've got a curious situation where we're getting regular ORA-01555 errors yet they don't seem correct. First a few things on the set up:
- 4-node RAC (+ 4-node RAC DG)
- RHEL 8 x 64GB servers
The query returned in the error is doing a full scan of a 3,100 row table, which takes less than 1 sec to complete. I've tried the same query repeatedly and it always takes less than one second, even when trying it while ORA-01555 errors are being returned saying that query is failing elsewhere. The query is run 10,000+ times per day, always run from the same node.
The ORA-01555 error lists this query as having a duration of around 12,000 seconds each time, which from what I can tell is impossible. Again, it's a 3,100 row table, no parallelism, 1 index (which isn't used by this query). I checked LAST_ANALYZED and the table hasn't been analyzed in 4 days. I checked DBA_TAB_MODIFICATIONS and it's had around 200 DML's since it was analyzed, but the last of which was 2 days ago.
So is Oracle returning the wrong query? Is the ORA-01555 bogus? Checking GV$UNDOSTAT, SSOLDERRCNT matches the # of ORA-01555 we're seeing (87 today, all the same query). All instances have the same UNDO_RETENTION (3600) and similarly sized undo tablespaces.
Any clues how to catch the trouble making queries?
Dave Herring | DBA, Global Technology Services
A c x i o m C o r p o r a t i o n
630-944-4762 office | 630-430-5988 cell | 630-944-4989 fax 1501 Opus Pl | Downers Grove, IL, 60515 | U.S.A. | www.acxiom.com Service Desk: 888-243-4566, https://servicedesk.acxiom.com, GSCA_at_DNB.com
The information contained in this communication is confidential, is intended only for the use of the recipient named above, and may be legally privileged.
If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited.
If you have received this communication in error, please resend this communication to the sender and delete the original message or any copy of it from your computer system.
-- http://www.freelists.org/webpage/oracle-l -- http://www.freelists.org/webpage/oracle-l -- http://www.freelists.org/webpage/oracle-lReceived on Mon Feb 08 2010 - 11:42:03 CST