FW: oracle database performance/availability/outage issue

  • From: "Powell, Mark D" <mark.powell@xxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Wed, 7 Feb 2007 13:49:54 -0500

Actually this parameter still exists in 9i and 10g with the default of 4
x TRANSACTIONS.  Still maybe a search on the parameter and 8.1 will turn
up something of use.
 

-- Mark D Powell -- 
Phone (313) 592-5148 

 


________________________________

        From: Powell, Mark D 
        Sent: Wednesday, February 07, 2007 1:34 PM
        To: oracle-l@xxxxxxxxxxxxx
        Subject: RE: oracle database performance/availability/outage
issue
        
        
        DML_LOCKS is a database parameter on version 8.1 that you can
still set.  You might need more that whatever the default is on your
system though I seem to remember the number 500 in relation to a limit
but my memory fails when ever I actually try to thing of a fact I need
at the time.
         
        
D S S M A
        
e e y o d
        NAME                            VALUE
f s s d j
        -------------------------------
----------------------------------- - - - - -
        DESCRIPTION
        ----------------------------------------------------------------
        dml_locks                       100
N N N N N
        dml locks - one for each table modified in a transaction
        
        -- Mark D Powell -- 
        Phone (313) 592-5148 
         


________________________________

                From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Alex zeng
                Sent: Wednesday, February 07, 2007 11:12 AM
                To: oracle-l@xxxxxxxxxxxxx
                Subject: oracle database performance/availability/outage
issue
                
                

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

                 

                Platform

                DB: 8.1.6

                OS: HP-UX 11.00 

                Hardware: PA-RISK, 8 cpu/16G memory

                 

                Symptom

                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. 

                Thanks
                
                Alex
                
                -- 
                --The mount is there. 

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