setting events
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Thread: setting events

  1. #1
    Join Date
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    setting events

    Hi everyone,
    I read about people preffering to set the event 10046 instead of setting SQL_TRACE=TRUE. What does it actually mean, setting an event?
    Are there other events that can be set? And why do some people claim that it could destabilise your system?
    Can someone throw some light?
    Thanks,
    Dorian

  2. #2
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    Last edited by akhadar; 09-28-2004 at 07:46 AM.

  3. #3
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    Question

    Just to share - as a warning:

    Config: WinNT with Application & 8i server on same box. We store Word docs, so have to run anti-virus, McAfee in this case.

    Setting event 10046 for the session from inside the application caused it to run 100x slower; server becomes CPU bound by McAfee. Trace file full of SQL*Net waits.

    I don't like my reasoning, but Oracle Support couldn't do any better: Somehow the combination of the application layer (?!) and McAfee slowed down the writing of the trace file, somehow this was reported as SQL*Net waits, which were written to the trace file. The slow writing of SQL*Net waits to trace was reported as SQL*Net waits, which in turn were written to the trace file . . . ad infinitum (almost).

    Setting event 10046 outside the application only had a 30% impact on performance. After turning off McAfee, setting event 10046 inside the application had only a 2x impact - negligible number of SQL*Net waits.

  4. #4
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    Originally posted by DaPi
    [B]Just to share - as a warning:

    Config: WinNT with Application & 8i server on same box. We store Word docs, so have to run anti-virus, McAfee in this case.
    B]
    Hi Dapi, I have seen Windows system running Oracle have problems with running anti-virus software. i.e. if you were to actively scan all files that are changing you could protentially corrupt some of you data files as well as severely limit performance. In my last company we told customers that we would not support their database unless they excluded the Oracle directories from active scanning.

    Do you exclude the Oracle directories from active scanning? Just the data directories, or do you also exclude the Oracle software directories including the trace file directories? Just curious.

  5. #5
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    Hi gandolf,

    Point taken - But haven't had any probs in 5 years . . .

    We only scan "incoming files" - which seems to be interpreted in this case as any file created. *Thinks* - then it will scan archive logs as well as the trace files.

  6. #6
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    How about Norton Antivirus sw?

    Tamil

  7. #7
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    (Had to run for a train, so didn't really finish above.)

    Should have said: ". . . only seems to scan files created or replaced". McAfee must get its hooks somewhere into the OS file handling.

    We didn't find a need to exclude any directories (that was in our early days - 7.3.4 with noarchivelog). I'll now try excluding the archlogs - I don't expect any noticable effect, except perhaps in over-night "batches", when there's no one to notice it.

    My ex-SA found out the hard way what scanning outgoing files does to OS backup times. And I found out how slow a restore is, if you forget to switch off the scanning!

    Tamil, I've never tried Norton on a DB server of any kind.

  8. #8
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    further thought:

    Under Windows "Direct I/O" is used - I suspect this does not allow any virus checker to get its hooks in: http://www.ixora.com.au/notes/direct_io.htm

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