RE: reading the SGA from my own program

From: Powell, Mark D <mark.powell_at_eds.com>
Date: Mon, 21 Aug 2006 13:01:30 -0400
Message-ID: <5A14AF34CFF8AD44A44891F7C9FF41050839CE9A@usahm236.amer.corp.eds.com>

The primary point of directly reading shared memory is that by doing so you bypass Oracle. So when the entire instance hangs and will not grant new connections you can go around the problem and see what is happening (or not happening as the case may be). You also avoid the latching overhead required for accessing the shared memory structures via Oracle. True, you may see some inconsistent data, but you will see it.  

HTH -- Mark D Powell --  

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        From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Allen, Brandon

	Sent: Monday, August 21, 2006 12:25 PM
	To: tanel.poder.003_at_mail.ee; anjo.kolk_at_oraperf.com;
jeremiah_at_ora-600.net
	Cc: Oracle Discussion List
	Subject: RE: reading the SGA from my own program
	
	
	Please forgive my ignorance, but what is the point of this

direct SGA access anyway? Why not just query v$session_event and/or v$session_wait, or the underlying x$ tables?          

	Thanks,
	Brandon

________________________________

	From: oracle-l-bounce_at_freelists.org


[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Tanel Poder

	Sent: Saturday, August 19, 2006 2:30 AM
	To: anjo.kolk_at_oraperf.com
	Cc: jeremiah_at_ora-600.net; 'Oracle Discussion List'
	Subject: RE: reading the SGA from my own program
	
	 
	Also, if all you're interested in is the current wait state of a

session, then there's no real fundamental need to map those SHM segments which do not contain the data you're interested in (as far as I understand).          

        Tanel.          

        . . .         

---

                                From: oracle-l-bounce_at_freelists.org
[mailto: oracle-l-bounce_at_freelists.org

<mailto:oracle-l-bounce_at_freelists.org> ] On Behalf Of Jeremiah Wilton

				Sent: Saturday, August 19, 2006 05:14
				To: 'Oracle Discussion List'
				Subject: reading the SGA from my own

program                                                                                            

                        I am trying to play around with reading the SGA using my own program, as popularized by Kyle Hailey and Miladin Modrakovic's papers and presentations. I am confused about where to find x$ksusecst (session wait) and other items in the fixed area.

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Received on Mon Aug 21 2006 - 12:01:30 CDT