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Conference ulysse::rdb_vms_competition

Title:DEC Rdb against the World
Moderator:HERON::GODFRIND
Created:Fri Jun 12 1987
Last Modified:Thu Feb 23 1995
Last Successful Update:Fri Jun 06 1997
Number of topics:1348
Total number of notes:5438

687.0. "Oracle files named [].;" by NZOV07::HOWARD (NZ: Where Digital's Week Begins) Tue Jul 10 1990 12:10

    When running Oracle Financials on VAX/VMS, our customer's users
    get satisfactory response, up to the point where they reach their
    WSEXTENT value (which is 8000).  This is when performing invoice entry.
   
    Thereafter, performance during commits gets progressively worse.
    
    Interestingly, the Direct I/O of the user process during commits
    climbs rapidly.  Further investigastion showed that on one disk
    the process was accessing a (not previouly present) file named 
    [].;
    
    An interesting name!.  If the user logs out, all reference to it
    disappears and upon login the users performance is back to normal
    (until WSEXTENT reached again.
    
    Anyone seen this before?.  Any ideas on what the file is used for?.
    The local O people have gone of to think about it.  I trust it's
    not a VMS cause.
    
    Cheers, Martin
T.RTitleUserPersonal
Name		DateLines
687.1Check REDO log diskMAIL::DUNCANGOracle... the one-line databaseFri Jul 13 1990 16:3312
    VMS does what Oracle tells it to so the problem is probably not
    related to VMS so don't let the Oracle guys come back with the "it's
    a VMS problem" crap.
    
    I assume you're talking about Oracle V6.  With that in mind, when
    Oracle V6 commits, there is ALWAYS i/o to the disk where the redo logs
    are located.  (The actual data pages are written to disk later.)  
    If you are experiencing excessive DIO, check the size of the redo logs
    and the various Oracle parameters that relate to log checkpoint
    intervals.
    
    -- gerry
687.2Yes, but why?NZOV07::HOWARDNZ: Where Digital's Week BeginsTue Jul 17 1990 01:5018
    Well the O people have admitted that their software calls the VMS
    system service used to create temorary files, and is passed null
    parameters hence the funny file names.
    
    The local office is still not sure WHY this is done and are "following
    it up".
    
    Interestingly we have increased user working set extents (WSEXTENT)
    to 20,000 so it is not for lack of memory.  Peak used so far is
    9950 (thats 5MB !).  Physical memory is only 60% used, as we are allowing
    for more users.
    
    A background process named SRV has been running with 2048 WSEXTENT.
    The O people have only just found the place in the ORACLE manual that
    explains how to increase that, so we wait to see if things get any
    better.
    
    Cheers, Martin
687.3Better?TRCA01::MCMULLENTue Jul 31 1990 21:575
    Martin,
    
    Did they get any better?
    
    Ken M
687.4NZOV07::HOWARDNZ: Where Digital's Week BeginsFri Aug 03 1990 14:2430
�    Did they get any better?
 
    Not yet.
    
    The O people have said that the problem will be present at ALL VMS
    sites (and possibly those on other platforms).  They are asking
    the head office to look into ways of either providing a workaround
    to bypass the hard-coded logic, or to provide a modification.
    No progress at the customer site so far.
    
    It seems that my customer processes large batches of invoices which
    cause the working set for the processes to just keep increasing.
     If they had smaller batches, and exited more often, the problem
    would not be seen.   
    
    The local O people (when prompted by the customer) admitted that
    other customers may have the problem and not realise it.
    
    SO IF YOUR CUSTOMER IS HAVING PERFORMANCE PROBLEMS WITH ORACLE
    FINANCIALS, do a   SHOW DEV/FIL  and look for those funny files.
     Also use   SHOW PROC/CONT  to monitor the process details.
    
    
    As an aside; it's interesting to see the positions at the customer
    meeting.  Some at Digital are very tolerant of customer demands
    through fear of losing the box sale.  Oracle are very slack in support
    letting issues drag on for weeks, but don't have to worry to the same
    degree becuase for them the customer is captive.
    
    Cheers, Martin