RE: ORA-04031 error while trying to load a PL/SQL object
- From: A Joshi <ajoshi977@xxxxxxxxx>
- To: john.kanagaraj@xxxxxxx, Amir.Hameed@xxxxxxxxx, oracle-l@xxxxxxxxxxxxx
- Date: Tue, 7 Feb 2006 06:05:22 -0800 (PST)
Long term : Have the application use bind variables.
If you are pinning : database startup is the best time to pin. Are you
pinning everyday and including new objects? Using algorithm? What does the
algorithm do? If you have such a big SGA : then maybe pin all active PL/SQL on
startup and forget it.
Can you tell the purpose of your flush? Please note that flush may not get rid
of fragmentation. Thanks
John Kanagaraj <john.kanagaraj@xxxxxxx> wrote:
Amir,
An ORA-4031 error on an Apps database needs to be considered in the same way
as a 'normal' database. It is probably caused some program or process that
executes a large number of small, non-resusable SQL. One normally thinks of
user written SQL, but I have seen a severe case of ORA-4031 caused by a cronjob
that regrants SELECT access to a read-account. The SQL generated thousands of
'grant select on <> to read_only_account' on all objects and held the shared
pool/lib cache latch for long periods, while polluting it with small statements
that broke up contiguos free space. Do you encounter lots of lib cache/shared
pool latching? If so, you must trace them to see where/why they occur and you
might discover the source of the 4031s.... YMMV!
Fyi, ORA-4031 is considered a 'user error', not a system error for whatever
reason. You need to have an entry in the init.ora using the event parameter for
an ORA-4031 error to be logged in the alert log. If you can check the older
init.ora for the 8i instance, you might see this... Btw, there was a nice
article from COE in either Metalink or OTN about the shared pool recently
(don't have the URL but it was mentioned in this list).
Let the list know if you come across something, since that is how we all
learn!
John Kanagaraj <><
DB Soft Inc
Phone: 408-970-7002 (W)
Co-Author: Oracle Database 10g Insider Solutions
http://www.amazon.com/exec/obidos/tg/detail/-/0672327910/
** The opinions and facts contained in this message are entirely mine and do
not reflect those of my employer or customers **
---------------------------------
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On
Behalf Of Hameed, Amir
Sent: Monday, February 06, 2006 1:32 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: ORA-04031 error while trying to load a PL/SQL object
Folks,
I have an 11i (11.5.0)/9.2.0.6 (64-bit) database running on Solaris 8 with the
following shared pool sizing:
Shared_pool: 1.2 GB
Db_cache_size: 6 GB
ODM is enabled and that is why the cache size is large.
We run hot backups on this database (using use-managed backup procedure) and
flush the shared pool every night after the hot backup (this process is
scripted into the backup process). I pin ~ 300 packages into SGA based upon an
algorithm in the pinning script. We had an issue this past Friday where some
concurrent programs failed and reported the following error in their log files:
-----
Cause: wiltbf failed due to ORA-04031: unable to allocate 43712 bytes of shared
memory ("shared pool","WIP_TRANSACTIONS_PKG","PL/SQL MPCODE","BAMIMA: Bam
Buffer")
ORA-06508: PL/SQL: could not find program unit being called
ORA-06512: at line 1
----
The action taken to remediate the problem was that we shutdown the concurrent
managers and then flushed the shared pool (without bouncing the database) and
the problem went away. I now have the following questions:
1. I have had this issue about two years ago when I was running 64-bit
8.1.7.4/11.5.6 but at that time Oracle had reported the ORA-04031 in the
database alert log file but this time it did not. I was expecting it to report
this message in the alert file. Could someone please explain whether this
message does not necessarily have to appear in the alert log file or that it
should have and that this might be a bug?
2. I was under the impression that the shared pool algorithm in 9i2 has
changed from 8.1.7.4 and that the shared pool fragmentation is not an issue
anymore; but it seems that I ran into a shared pool fragmentation scenario and
even with the daily flush, the shared pool still got extremely fragmented.
Prior to the past week, we used to bounce the database every night after the
backup but we stopped doing that about 8 days ago and I believe that it
contributed to the shared pool fragmentation. Is flushing the shared pool on
daily basis not enough to cleanup fragmentation if one wants to keep the
instance running for weeks?
Any feedback will be appreciated.
Regards
Amir
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