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RE: x$ constructs and memory

From: Orr, Steve <>
Date: Mon, 29 Sep 2003 08:44:39 -0800
Message-ID: <>

> What happens when these x$constructs begin to consume large
> amounts of memory? Is there an upper bound?
Dan, can you think of a scenario where X$ constructs could consume enough memory that DBA marmots like us should meditate on them?

OT: Are there many grizzlies in CO? There are plenty here in MT and I always take my pepper spray with me whenever if go to the mountain top to comtemplate things Oracle and otherwise. Got within 100 yards of one and I saw him but he didn't see me.

Steve Orr
Bozeman, Montana

-----Original Message-----
Sent: Monday, September 29, 2003 9:45 AM To: Multiple recipients of list ORACLE-L

You should have asked a grizzly bear. They're much wiser then marmots and they don't
run away that easily. Also, when you see a grizzly bear 100ft away from you and realize
that you only have a camera with you, then you begin to understand that there are bigger
worries in this world then the location of database structures. What a grizzly would tell you is that, according to my sources, those tables are stored
in the "misc" area of shared pool, which can easily be seen when selected * from V$SGASTAT.
Here is what a grizzly would have in mind:

POOL        NAME                            BYTES
----------- -------------------------- ----------
shared pool 1M buffer                     2098176
shared pool KGLS heap                     4102928
shared pool PX subheap                      76920
shared pool parameters                      32796
shared pool free memory                 101833708
shared pool PL/SQL DIANA                  1028660
shared pool FileOpenBlock                 3476816
shared pool PL/SQL MPCODE                  547852
shared pool library cache                30858108
shared pool miscellaneous                11656764
shared pool pl/sql source                    2708

Mladen Gogala
Oracle DBA

> -----Original Message-----
> From: [] On
> Behalf Of Daniel Fink
> Sent: Monday, September 29, 2003 11:10 AM
> To: Multiple recipients of list ORACLE-L
> Subject: x$ constructs and memory
> 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
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Received on Mon Sep 29 2003 - 11:44:39 CDT

Original text of this message