SGA, PGA & RAM Size?

our DB running in dedicated server mode(FYI).
am defining my SGA size 500MB, which is half the size of DB server 1gb RAM, it does not mean that my instance will not go beyond 500mb, if multiple users are connected & start using Sorts,(SORT_AREA_SIZE =1mb), apart from 500mb, each user whoever using sort area space will be allocated 1mb space in 1gB RAM, is it correct?
since SORT_AREA_SIZE can be modified at session level,each user can set their own sort area size, which may lead to paging, is it correct?
Sorts uses memory from PGA,PGA is not part of SGA,hence how to determine the PGA size?, is there any init.ora parameter for sizing PGA in ORACLE 8.1.7?

The size of PGA will depends upon the containts of PGA which are Sort Area, Session Statistics Information, Stack Space, Cursor Information
I am not aware of any parameter to size the PGA.
I will check the documentation and will let you know.
Manu

Similar Messages

SGA+PGA Size allocation

Hi all
I Have a server System Configuration with
RAM size: 16GB Ram & Hard disk Size of 1TB.
I Installed Oracle 11g R2 in the server System
I want to Allocate Dedicated Memory for oracle..
How Should i calculate the Memory size of SGA+PGA for good Performance..

Pl do not post duplicates - Reg:-SGA & PGA Memory Allocation Size

Reg:-SGA & PGA Memory Allocation Size

Hi all
I Have a server System Configuration with
RAM size: 16GB Ram & Hard disk Size of 1TB.
I Installed Oracle 11g R2 in the server System
I want to Allocate Dedicated Memory for oracle..
How Should i calculate the Memory size of SGA+PGA for good Performance..

Check MOS
*How to calculate the memory used by dedicated and shared servers? [ID 551415.1]*

SGA/PGA Sizes ???

I need help!
I have a Windows 2003 Server (w/sp2) with 4GB of RAM & 2 CPUs. Oracle 10.2.0.2 is installed.
ASMM is ENABLED by default (and it still is)
These are my sga/pga settings:
pga_aggregate_target = 1G
sga_max_size = 1504M
sga_target = 1000M
shared_pool_size = 504M
sort_area_size = 262144000 (250M)
large_pool_size = 104M
db_cache_size = 104M
I believe I should DISABLED ASMM, correct? Otherwise, my settings aren't used.
Based on my 4GB, I think Oracle can use 2GB of that.
What should I set the settings above too?
...thanks

First if you use Oracle's automatic memory management feature and provide spfile parameter values for parameters that are automatically managed by Oracle then the provided values are taken as minimum values for these areas. There are other situations where values for parameters like sort_area_size which is limited to 5% of pga_aggregate_target are in fact still referenced.
With a pga_aggregate_target of 1G I do not see any valid reason why you would have a sort_area_size set to 250M. What is the reason for this?
What kind of environment is this: OLTP, DSS, OLAP?
How many concurrent sessions?
Dedicated vs shared server?
Why do you not want to use automatic memory management? What problem have you encountered?
HTH -- Mark D Powell --

I want SGA size=4GB when RAM size=8GB.

Hello,
If i am not wrong, oracle takes the 40% of RAM size by default for SGA. At one of my clients site server, they have 8 GB RAM , now i wanted to a lot them at least 3GB to 4GB RAM for SGA. As i tried to do so , it was not taking more than 2GB ...
Why oracle does not take SGA size more than 2GB ? how can this be increased ? can someone please put some light on this point.
ORACLE 10G R2
Windows Server 2005
Thanks and Regards,

Hello,
In Windows *32 bit* you are limited to *2GB* per process (whatever the process). So the Process oracle.exe
cannot overcome this limit except if you use the */3GB* parameter.
So if you want to have a larger SGA you should think to migrate to a *64 Bit* OS. But keep in mind that having
large SGA is not the only way of tuning a database.
Please find enclosed a link about this topic:
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:707585800346136316
Hope this help.
Best regards,
Jean-Valentin
Edited by: Lubiez Jean-Valentin on Mar 26, 2010 10:04 PM

Oracle 11g SGA & PGA setup

Hi I installed oracle 11g & create database , now i want to use fully optimize database.
Currently my DB server RAM is 16GB, how should i allocate SGA for this.If i used oracle 11g automatic memeory management feature to allocate SGA+PGA, how should i use them.Currentlymy SGA is set to 4GB, Please advise

Hi,
It is depends upon the workload which you have in your organization(future and present situation)
SGA+PGA size will be automatically managed by Oracle. No need to worry about this.
If you need to increase Memory_Max_Size, you can also increase the Memory size in the future.
Thanks

SGA & PGA target

Hi all,
My questions is regarding how to set up SGA & PGA target values giving DB server is MS 2003 Enterprise 64 edition sever with 63 GB of RAM. Our DB’s version is 10.2.0.3 and RACed with 2 instances.
Currently our setting for SGA is 23 GB and PGA is 4 GB. I ran the memory advisor it display different optimal values for those two instances (35 GB and 23 GB for SGA, 5 GB and 4 GB for PGA). Guess our db is not well balance loaded.
I would like to know if there is any rule(s) that SGA can’t be more than certain percentage of total RAM for the server.
Thanks a lot in advance.
Have a great weekend!!
Shirley

Hi
Here is my approach:
1) consider free physical memory (meassure must be taken with Oracle down)
2) substract a 10% of that amount as a margin
3) if the box is exclusive for Oracle, the remaining amount may be your SGA+PGA limit
4) if not is exclusive, then substract memory required for other services, then you'll get the SGA+PGA limit.
5) Substract your PGA size, giving the SGA figure
For instance
59 Gb - 6 Gb = 53 Gb - 4 Gb = 49 Gb
(63 Gb -4 Gb [estimated OS footprint + IO cache]) = 59 Gb free physical memory
Setting PGA+SGA beyond the free physical memory figure, may lead to swaping and degraded system performance.
Regards
http://oracledisect.blogspot.com

SGA/PGA (Memory) in RAC environment.

Guys,
I would like to get your inputs on SGA / PGA settings on a RAC database.. Does LMS/LMON/LMD process use memory which is part of PGA or these process allocate memory at OS level ?
I would like to see the usage of Memory used by a database.
below sql from Mr. Kyte's website i have used. Somehow i am not getting real usage of the system. Any help would be appreciated.
Thanks
select
ssst.sid,
stn.name ,
round(ssst.value/1024/1024,2) memory ,
USERNAME,
COMMAND,
OSUSER,
MACHINE,
TERMINAL,
PROGRAM ,
ssst.STATISTIC#
from v$statname stn,v$sesstat ssst , v$session ses
where stn.STATISTIC# = ssst.STATISTIC# and
ssst.sid = ses.sid and
name like 'session%pga%memory%'
order by 3 asc ;
Edited by: P explorer on Aug 28, 2009 9:56 PM

From sql script, that get "session pga memory","session pga memory max" each of session in oracle database(on that node)
You'll see
sid: session id
memory:
if "session pga memory" = pga memory in this session now
if "session pga memory max"= maximum pga memory in this session.
program: os program name
More deatails abour v$session http://download.oracle.com/docs/cd/B19306_01/server.102/b14237/dynviews_2088.htm#REFRN30223
If need to know all PGA size in that node
"session pga memory":
select
round(sum(ssst.value)/1024/1024,2) memory
from v$statname stn,v$sesstat ssst , v$session ses
where stn.STATISTIC# = ssst.STATISTIC# and
ssst.sid = ses.sid and
name ='session pga memory';
"session pga memory max":
select
round(sum(ssst.value)/1024/1024,2) memory
from v$statname stn,v$sesstat ssst , v$session ses
where stn.STATISTIC# = ssst.STATISTIC# and
ssst.sid = ses.sid and
name ='session pga memory max';
Or if you need to check PGA memory all nodes (RAC)
COLUMN username FORMAT A20
COLUMN module FORMAT A20
SELECT a.inst_id,
NVL(a.username,'(oracle)') AS username,
a.module,
a.program,
Trunc(b.value/1024) AS memory_kb
FROM gv$session a,
gv$sesstat b,
gv$statname c
WHERE a.sid = b.sid
AND a.inst_id = b.inst_id
AND b.statistic# = c.statistic#
AND b.inst_id = c.inst_id
AND c.name = 'session pga memory'
AND a.program IS NOT NULL
ORDER BY b.value DESC;

Sga&pga

Hi all;
i wanna learn something about sga and pga... I have r11 instance on linux and db version is 10.2.0.3...Let say my sga=5 Gb and pga is=3gb...my server has 20gb ram...when i look my usage by top command and i see that:
Mem: 20550320k total, 20491732k used why linux allocate all those area?
i have 20 Gb ram and sga+pga=8 soo which oracle process use 12 Gb?
and advicer gives me adivice about SGA... it offers 10 Gb SGA... if i rise my sga what is my benefit? what it would change?
thanks alot

Hi hussien;
Thanks for again answers and help
You need to identify what other processes are running on this node. For example, if you have CM running on the database tier node, then it is expected to find more memory allocated. You can simply stop all the services on the server and start it one by one, and each time and keep an eye on the allocated memory.Its my mistake, coz i talked wiht my client and they said me they are working on this machine and thatswhy i had this memory usage.. sory for this mistake again (but your post helped me alot,coz i asked them what they are doing for a now ,and they gave me that answer :),thanks for leading)
Since you are on 10g, I would suggest you also go through the following document.
Note: 295626.1 - How To Use Automatic Shared Memory Management (ASMM) In Oracle10g
https://metalink2.oracle.com/metalink/plsql/ml2_documents.showDocument?p_database_id=NOT&p_id=295626.1
If you still have any queries, please feel free to post it here.Thanks for note.. i am reading it and its soo usefull for me, thanks for sharing your knowledge here wiht us hussein..
you are an oracle angle :)
regards
Helios
Edited by: helios on 12.May.2009 06:58

Kernel para and sga,pga sizing

Hello,
OS-HP-UX(configured to use high sga /no restrictions)
Current database is running without any issue
Due to increase in physical ram i plan to increase sga and pga(ram is increase about 3 times)
My question:
1)should i also increase sga and pga in same propotion (3 times then existing)
or use 70% ROT formula
2)whatever figure i arrive by analysis for increasing sga,do i need to change kernel parameters also
(does i requre to change kernel parameter every time ram and sga is increased)
Please suggest
Thanks

880991 wrote:
Ok some questions based on your reply:
1)then how any gain in upgrading memory above 4 GB if shmmax cannot be more then 4 GB (32 bit OS),then
SGA also cannot be > 4GB (As per documents SHMMAX should be > SGA)Because the SGA doesn't have to be in one segment. Which version of Oracle are you looking at? It makes a difference!
http://kevinclosson.wordpress.com/2009/07/27/little-things-doth-crabby-make-part-x-posts-about-linux-hugepages-makes-some-crabby-it-seems/
>
2)I read if Operating system is linux can use SGA above 4GB,in fact one of friend told they implemented SGA
4GB on linux configuring VLM/Huge pages,so in that case ( VLM ) needs to set SHMMAX > 4GB (as per memory ROT) of VLM take cares of SGA > 4GB even if SHMMAX is not setintrestingly my friend also mentioned that in there server VLM is set and shmmax is set < 4 GB and SGA > 4GB
still it works without problem when checking SGA usage in dyanamic views its shown as using above 4 GB
,it contradicts what i read in documents,how this is working ,anyone have idea?[url http://download.oracle.com/docs/cd/B28359_01/server.111/b32009/appi_vlm.htm]No contradiction.
Also VLM implementation is restricted to Linux or it can be on set on Unix as well and if its set do all components
of SGA benefit or only buffer cache?
ThanksIt varies, some unix are quite different than others. Specific answers can only be given to specific configurations. I really have to wonder when you are asking about hp-ux and 32 bit.

SGA, PGA and SHMMAX Setting

If I have set SHMMAX to 8GB (on 64bit linux) value, does that mean that my SGA+PGA values need to remain within 8GB limit? If my SGA size is 6GB and PGA size is 4GB, does that mean that my OS is going to allocate two shared memory segments?

The SHMMAX parameter is used to define the maximum size (in bytes) for a shared memory segment and should be set large enough for the largest SGA size.
http://www.idevelopment.info/data/Oracle/DBA_tips/Linux/LINUX_8.shtml
http://books.google.co.in/books?id=2ImPFP6Yk64C&pg=PA357&lpg=PA357&dq=PGA+is+included+in+SHMMAX&source=bl&ots=On3S7-CEX0&sig=LhOYOO946hrPZh-cIUEzWNiwpRg&hl=en&ei=xyLOTJqaC4yYvAONm7T3Dw&sa=X&oi=book_result&ct=result&resnum=5&ved=0CCwQ6AEwBA#v=onepage&q&f=false
Please close the thread as answered.

Mixing ram SIZES in Late 2013 i7 27" iMac

Just assume all ram sticks are the same specs.......
Can I mix ram SIZES in Late 2013 i7 27" iMac? I.E. : two - 4 GB and two - 8 GB?

You should try to balance RAM out as equally as possible between available slots.
For example, 2 4 4 4, 2 2 4 4, 2 2 2 4, but not 2,4,8,0. And where you only have two slots, 2 2, 2 4, 4 4, and so on.

Increased RAM size

Hi all,
i have increased RAM size to 32 GB in our production server. currently we have 40 GB of SWAP. now i want know how to distribute the RAM size to database , SAP and operating system. please let me know the parameters for increase.
Operating system : SuSE 10 SP2
Database : oracle 10.2.0.2
SAP : SAP ECC 6.0 SR2 (ABAP stack only)
ztta/roll_area        6500000
ztta/roll_first       1
ztta/short_area       4000000
rdisp/ROLL_SHM        32768
rdisp/PG_SHM          32768
rdisp/PG_LOCAL        150
em/initial_size_MB    5120
em/blocksize_KB       4096
em/address_space_MB   4096
ztta/roll_extension   2000000000
abap/heap_area_dia    2000000000
abap/heap_area_nondia 2000000000
abap/heap_area_total 2000000000
abap/heaplimit        40000000
abap/use_paging       0
please give you valuable suggestions and whether it is required to increase the swap size
regards
Ramesh
Edited by: Ramesh Sammiti on Oct 26, 2009 10:54 AM

As this is production system, you better go with SAP's recommendations.
You do Zero memory (Default memory parameters) open an OSS message and probably
you can do quick sizer modeling also.
service.sap.com/quicksizer
All the best,
Nagaraju

SGA, PGA and... little extra?

Will oracle process use some extra "non oracle" memory for OS related stuff?
Mean, not considering SGA, I connect a database process and I see:
SQL> select p.program,
2 p.spid, pm.category, pm.allocated/1024 allocated, pm.used/1024 used, pm.max_allocated/1024 max_allocated
3 from V$PROCESS p, V$PROCESS_MEMORY pm
4 where p.pid = pm.pid
5 and p.spid =2650;
                                                                                                        Max
                                                                          Allocated       Usedd   allocated
PROGRAM                        SPID                     CATEGORY                 Kb          Kb          Kb
oracle@uxlabhost11             2650                     SQL                      14           9          42
oracle@uxlabhost11             2650                     PL/SQL                   56          34          57
oracle@uxlabhost11             2650                     Other                  1501                    1501That's allocated PGA after having connected and done nothing else
So it somehow allocated 1.4 Mb upon start-up...
Now question is. Do oracle processes use OS memory which cannot be considered as SGA or PGA?
Reason being my trying to estimate memory needs for a database server. Many I've read correct formula should be SGA + max allocated PGA + some_extra_just_in_case...
Is there an estimate on how much that "some_extra_just_in_case" would be per process?
If OS dependent, I'm implementing on RHEL 6...
thanks

So, I've used pmap...
Got 257 enties in the form "4096K rw-s- /dev/shm/"
since we are using AMM , that should do for PGA and SGA ... some 1052672 Kb, which process is attached to...
yet pmap then continues to display other entries....
0000002a95557000      4K r-x-- /opt/oracle/product/11g/lib/libodm11.so
0000002a95558000   1024K ----- /opt/oracle/product/11g/lib/libodm11.so
0000002a95658000      4K rw--- /opt/oracle/product/11g/lib/libodm11.so
0000002a95659000      4K rw---    [ anon ]
0000002a9565a000    392K r-x-- /opt/oracle/product/11g/lib/libcell11.so
0000002a956bc000   1024K ----- /opt/oracle/product/11g/lib/libcell11.so
0000002a957bc000     40K rw--- /opt/oracle/product/11g/lib/libcell11.so
0000002a957c6000      4K rw---    [ anon ]
0000002a957c7000    864K r-x-- /opt/oracle/product/11g/lib/libskgxp11.so
.. TRUNCATED...
0000003fb810a000     64K rw---    [ anon ]
0000003fbbd00000     84K r-x-- /lib64/libnsl-2.3.4.so
0000003fbbd15000   1020K ----- /lib64/libnsl-2.3.4.so
0000003fbbe14000      4K r---- /lib64/libnsl-2.3.4.so
0000003fbbe15000      4K rw--- /lib64/libnsl-2.3.4.so
0000003fbbe16000      8K rw---    [ anon ]
0000007fbffde000    136K rwx--    [ stack ]
ffffffffff600000      4K r-x--    [ anon ]
total          1276452KNotice "total 1276452K"
So you saying non SGA/PGA would be 1276452 - 1052672?
That would be too much... yet if pmap another process, almost all flags (hex column) but [ stack ] are the same....
So how to tell which of those are shared and which are "exclusive" to the process, i.e: The "some extra just in case" mem...
thanks

SGA & PGA Optimization

Hi to All,
Exist a method in order to optimize SGA & PGA, installing a DB in Oracle DB 10g?
Best Regards
Gaetano

Automatic Shared Memory Management(ASMM)
Requirements:
SGA_TARGET >0
STATISTICS_LEVEL=TYPICAL or ALL.
The below mentioned parameters are auto-tuned by oracle.
SHARED POOL
LARGE POOL
JAVA POOL
DB CACHE
Refer to Note:295626.1 from Metalink.(SGA)
Refer to Note:223730.1 from metalink (PGA)

SGA, PGA & RAM Size?

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