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RE: x$ constructs and memory

From: Hately, Mike (LogicaCMG) <>
Date: Mon, 29 Sep 2003 07:29:34 -0800
Message-ID: <>

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.

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

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Author: Hately, Mike (LogicaCMG)

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Received on Mon Sep 29 2003 - 10:29:34 CDT

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