Oracle FAQ Your Portal to the Oracle Knowledge Grid

Home -> Community -> Mailing Lists -> Oracle-L -> RE: oracle database performance/availability/outage issue

RE: oracle database performance/availability/outage issue

From: Kerber, Andrew <>
Date: Wed, 7 Feb 2007 10:17:06 -0600
Message-ID: <>

Sounds like you need to increase the number of available latches. Arent there some init.ora settings for that?  

Andrew W. Kerber
Oracle DBA
UMB     "If at first you dont succeed, dont take up skydiving"

-----Original Message-----

[] On Behalf Of Alex zeng Sent: Wednesday, February 07, 2007 10:12 AM To:
Subject: oracle database performance/availability/outage issue  

If you have such experience or insight to the issue, please kindly provide your help.  


DB: 8.1.6

OS: HP-UX 11.00

Hardware: PA-RISK, 8 cpu/16G memory  


  1. DB operation on data dictionary (such as create table) is hung. All are hung at 'latch free' events. The latch name is 'dml lock allocation'.
  2. # of DB processes will climbing up till maximum connections (150); then the database is unavailable to all new connections
  3. Before # of DB processes overflow, some DB light operations on user table are not affected, but not all. Huge operations (such as backend job) on user tables are hung too because it might trigger data dictionary operation.

What actions have been taken, are being taken or need to be taken

  1. Disabled large jobs such - in vain
  2. Restarted database - in vain. This helps little. After times passes, the number of processes will climb up and database goes down again eventually.
  3. Upper processes limit to 250 in database - GDBA is helping to make the parameter change right now and the database will restart soon. But I don't think this can resolve the issue. It only delays the outage.
  4. Logged TAR to metalink - 8.1.6 is out of support scope now. The possibility to get support form Oracle Corp is low.
  5. Further investigation needs to be taken upon the "data dictionary" hung/latch free event. This is where we need your suggestion and help.



--The mount is there.

NOTICE: This electronic mail message and any attached files are confidential. The information is exclusively for the use of the individual or entity intended as the recipient. If you are not the intended recipient, any use, copying, printing, reviewing, retention, disclosure, distribution or forwarding of the message or any attached file is not authorized and is strictly prohibited. If you have received this electronic mail message in error, please advise the sender by reply electronic mail immediately and permanently delete the original transmission, any attachments and any copies of this message from your computer system. Thank you.

-- Received on Wed Feb 07 2007 - 10:17:06 CST

Original text of this message