I was not directly involved with that particular discussion. But one of the things that I remembered (and played with, not in production yet!) is to create 'dual' as a view using 'select dummy from x$dual;' This causes less number of Logical IOs. In addition, creating an index on dummy can also help. I have not tested that part yet. Cary Millsap mentioned it in one of his e-mails. From what I understand the nunber of LIOs is Oracle version dependent and 9i uses the least. Gaja had suggested to recreate 'dual' as an IOT. Anjo Kolk mentioned that Oracle has been using x$dual in RMAN code.
HTH, - Kirti -----Original Message----- Sent: Thursday, May 30, 2002 12:49 PM To: Multiple recipients of list ORACLE-L Dan: The discussion was recent, but I cannot find reference to it. I kinda thought Kirti was involved in the thread, and it had something to do with creating an x$dual table as a workround to hammering dual. Sorry I can't remember any more . . . Barb > ---------- > From: Fink, Dan[SMTP:[EMAIL PROTECTED]] > Reply To: [EMAIL PROTECTED] > Sent: Thursday, May 30, 2002 10:23 AM > To: Multiple recipients of list ORACLE-L > Subject: Using DUAL > > The developers here have a fondness for using DUAL for simple operations > (select count(*) from dual is executed 10000+ times per day). I recall a > passing comment somewhere/sometime that there are performance issues with > accessing DUAL. Of course, now that I need to provide some information to > the developers, I can't recall the comment or find documentation. > > Any assistance is greatly appreciated. > > Daniel W. Fink > > -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Baker, Barbara INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Deshpande, Kirti INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
