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RE: Automatic Shared Memory question

From: Allen, Brandon <>
Date: Mon, 21 Aug 2006 11:04:01 -0700
Message-ID: <04DDF147ED3A0D42B48A48A18D574C45059E1D2E@NT15.oneneck.corp>

Yeah, I heard that too (on this list, I think). In my case, "KGH: NO ACCESS" consistently hogs about 800MB-1GB of my 2.4GB SGA though. I think maybe it just keeps it aside just in case it might need to add it to the buffer cache some day. Here is the exact definition I got from Oracle Support:

"KGH is Oracles internal memory management allocator. Most information regarding this memory management structure is proprietary."

Here are the specifics on my parameters and current stats, notice v$sgastat totals about 3.5GB even though sga_target and sga_max_size are only 2.4GB:

SQL> show parameter sga

NAME                                 TYPE        VALUE

------------------------------------ ----------- -----------------
lock_sga boolean TRUE pre_page_sga boolean FALSE sga_max_size big integer 2432M sga_target big integer 2432M
SQL> show sga

Total System Global Area 2550136832 bytes

Fixed Size                  2073416 bytes
Variable Size            1107299512 bytes
Database Buffers         1426063360 bytes
Redo Buffers               14700544 bytes

SQL> select sum(value) from v$sga;



SQL> select sum(bytes) from v$sgastat;



SQL> select * from v$sgastat where bytes > 10000000 order by 3;

POOL         NAME                            BYTES

------------ -------------------------- ----------
shared pool kglsim heap 10886400 shared pool object queue 10972224 shared pool private strands 11624448 shared pool Cursor Stats 12810416 log_buffer 14700544 shared pool kglsim object batch 14826168 shared pool KQR M PO 16347376 java pool free memory 16777216 shared pool ASH buffers 19922944 shared pool obj stat memo 21729000 shared pool PCursor 28763720 shared pool KGLS heap 30683152 shared pool CCursor 36028824 shared pool library cache 40596888 large pool free memory 62076128 shared pool sql area 162101816 shared pool free memory 503130768 shared pool KGH: NO ACCESS 1088472544 buffer_cache 1426063360

19 rows selected.

From: Charles Schultz [] Sent: Monday, August 21, 2006 10:54 AM
To: Allen, Brandon
Cc:; ORACLE-L Subject: Re: Automatic Shared Memory question

Someone told me (Oracle Support? Someone here?) that SGH: NO ACCESS is actually a transfer of data between the buffer cache and the shared pool. Ours was growing quite large under ASMM. Oracle Support never give us the skinny on exactly how it was allocated.

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Received on Mon Aug 21 2006 - 13:04:01 CDT

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