As I understand it, the X$ information is largely a window onto the control structures in shared memory rather than a summary, aggregation or abstraction. I may be wrong here but that's the way I've always understood it to work. So the structures 'occupy' the same space as the data they're supposed to reflect.
If I'm wrong I'd be interested to know the true story. Cheers, Mike HAtely -----Original Message----- Sent: 29 September 2003 15:10 To: Multiple recipients of list ORACLE-L I was sitting on a mountain here in Colorado, pondering Oracle optimization and an interesting scenario crossed my feeble mind. As I began to ponder this (I asked the resident marmot, but he must be a SQL*Server expert...), I came up with several questions. Where in memory (sga or other) do the x$ constructs reside? Some of them are 'populated' by reading file-based structures (control file, datafile headers, undo segments). Does this information reside in memory or is it loaded each time the x$ construct is accessed? What happens when these x$constructs begin to consume large amounts of memory? Is there an upper bound? Daniel Fink ******************************************************************************************** E mail Disclaimer You agree that you have read and understood this disclaimer and you agree to be bound by its terms. The information contained in this e-mail and any files transmitted with it (if any) are confidential and intended for the addressee only. If you have received this e-mail in error please notify the originator. This e-mail and any attachments have been scanned for certain viruses prior to sending but CE Electric UK Funding Company nor any of its associated companies from whom this e-mail originates shall be liable for any losses as a result of any viruses being passed on. No warranty of any kind is given in respect of any information contained in this e-mail and you should be aware that that it might be incomplete, out of date or incorrect. It is therefore essential that you verify all such information with us before placing any reliance upon it. CE Electric UK Funding Company Lloyds Court 78 Grey Street Newcastle upon Tyne NE1 6AF Registered in England and Wales: Number 3476201 ******************************************************************************************** -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Hately, Mike (LogicaCMG) INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- 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).
