RE: Automatic Shared Memory question
- From: "Allen, Brandon" <Brandon.Allen@xxxxxxxxxxx>
- To: "Charles Schultz" <sacrophyte@xxxxxxxxx>
- Date: Mon, 21 Aug 2006 11:04:01 -0700
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;
SUM(VALUE)
----------
2550136832
SQL> select sum(bytes) from v$sgastat;
SUM(BYTES)
----------
3657699704
SQL> select * from v$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 [mailto:sacrophyte@xxxxxxxxx]
Sent: Monday, August 21, 2006 10:54 AM
To: Allen, Brandon
Cc: Harvinder.Singh@xxxxxxxxxxxxx; 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.
Privileged/Confidential Information may be contained in this message or
attachments hereto. Please advise immediately if you or your employer do not
consent to Internet email for messages of this kind. Opinions, conclusions and
other information in this message that do not relate to the official business
of this company shall be understood as neither given nor endorsed by it.
--
//www.freelists.org/webpage/oracle-l
Other related posts:
