SGA components

hai
SGA contains many other structures apart from shared pool buffer etc.
and they are as given below
-lock and latch management
-statistical data
the question is that what basically these terms mean and what meaning they are having here in oracle.

Search the docu set please -- you'll get definitions, context and even something to reference. These are examples from two quick searches:
http://download.oracle.com/docs/cd/B19306_01/server.102/b14220/consist.htm#sthref2142
http://download.oracle.com/docs/cd/B19306_01/server.102/b14211/instance_tune.htm#sthref1030
http://download.oracle.com/docs/cd/B19306_01/server.102/b14211/instance_tune.htm
http://download.oracle.com/docs/cd/B19306_01/server.102/b14237/stats002.htm#i375475
http://download.oracle.com/docs/cd/B19306_01/server.102/b14211/stats.htm

Similar Messages

(10g)SGA_TARGET 파라미터를 이용한 AUTOMATIC MANAGMENT SGA COMPONENTS

제품 : ORACLE SERVER
작성날짜 : 2004-04-26
PURPOSE
이 문서는 SGA_TARGET 이라는 새로운 파라미터를 이용하여 Automatic
management SGA Components에 대하여 알아보기로 한다.
Explanation
SGA_TARGET 파라미터를 이용한 Automatic management SGA Components에 대하여
설명하기로 한다.
Automatic management SGA Components using SGA_TARGET
Oracle 10g부터 다음과 같은 각각의 SGA component에 대한 값들을 manual하게
설정할 필요가 없다.
shared_pool_size
log_buffer
java_pool_size
large_pool_size
buffer_cache_size
위 SGA 파라미터들의 사이즈를 측정하고 initSID.ora file에 그 값을 설정할
필요가 없음을 의미한다. 사실 SGA 크기를 정의하는 위 파라미터들을 설정하지
않아도 된다.
다만 10g 에서는 SGA_TARGET 이라는 새로운 파라미터만 셋팅하면 된다.
SGA_TARGET 이라는 파라미터는 해당 instance에 필요한 SGA의 최대 크기를
가리킨다.
SGA_TARGET을 152M 로 잡았다고 가정하자. 이것은 SGA가 커질 수 있는 최대 크기가
152M 라는 의미이다. Shared pool, buffer cache, large pool, java pool 과 같은
SGA component들은 이 maximum 사이즈 내에서 할당될 것이다.
오라클은 이러한 component들의 초기 값을 자동으로 계산하고 필요에 따라
자동으로 resize한다.
즉, SGA_TARGET 만 셋팅되어 있으면 shared pool, buffer cache, large pool,
java pool에 대하여 값을 명확히 지정할 필요가 없다.
Example
SGA_TARGET=152M 로 잡았다고 가정한다.(block size is 8K).
SQL> show parameter sga_target
NAME TYPE VALUE
sga_target big integer 152M
오라클은 다음과 같이 SGA component들의 사이즈를 정의한다.
SQL> show sga
Total System Global Area 159383552 bytes
Fixed Size 769328 bytes
Variable Size 72270544 bytes
Database Buffers 62914560 bytes
Redo Buffers 23429120 bytes
여기서 주목할 점은 다음과 같다.
1) SGA_TARGET을 셋팅하면 SGA_MAX_SIZE 의 값은 또한 SGA_TARGET 으로 셋팅된다.
즉, SGA_TARGET = SGA_MAX_SIZE.
SQL> show parameter sga
NAME TYPE VALUE
lock_sga boolean FALSE
pre_page_sga boolean FALSE
sga_max_size big integer 152M
sga_target big integer 152M
2) SGA_TARGET 의 값을 SGA_MAX_SIZE보다 더 크게 설정할 수 없다.
즉, SGA_TARGET <= SGA_MAX_SIZE.
SQL> alter system set sga_target=160M;
alter system set sga_target=160M
ERROR at line 1:
ORA-02097: parameter cannot be modified because specified value is invalid
ORA-00823: Specified value of sga_target greater than sga_max_size
Reference Documents
<Note:256913.1>
Oracle Database Concepts 10g Release 1 (10.1)
Part No. B10743-01
Chapter 8: Memory Architecture

842638 wrote:
hi experts.. please answer the question
Im on 10.2.0 linux....
sga_target=200m
sga_max_size=400m
if automatic components take 180MB out of 200MB and lets say manaul components take 10M. so is the remaing 10MB wasted? yes or noWhy wasted? Only after giving memory to the manual components, whatever is left would be given to the automatic components. So nothing would be wasted by this approach.
HTH
Aman....

Oracle SGA components manual allocation

All,
Phyical memory : 420G My database version : 11.2.0.3 running on linux machine.
Memory_target = 200G . I would like to allocate this value to following SGA components. I don't want to automatic memory management enabled. Can you please guide me how to split 200G for following components. Is there any percentage for each components ?
db_cache_size
db_recycle_cache_size
db_keep_cache_size
large_pool_size
java_pool_size
shared_pool_size
pga_aggregate_target
streams_pool_size
log_buffer
Thanks

There is no 'default' settings for the components. Oracle tell you, when you create a database with DBCA, that the values provided by that tool are for a sample database and you should tune them to how you see fit.
This is what I would do (assuming this is a test environment, of course):
- If you're using HugePages, disable it.
- Run with AMM but give some key components a 'minimum' value (such as SGA, PGA, shared_pool, etc) so it's not too crazy. Setting everything at 0 can have performance issues with some databses, strangely.
- Run an entire workload cycle (day, week, etc) - enough batch processing to mimic a realistic workload on Production
- Check out the dynamic views/AWR reports to see what the database advises with the various components.
- If you want to use HugePages, then set the SGA and PGA to whatever you've determined from the AWR reports. You can choose whether to specify minimum values for the SGA components.
- If you're not using HugePages, you really should use AMM. What I do is give the SGA and PGA minimum values and allow the database to decide which one gets the 'extra' memory that's left over. That way, the SGA doesn't drop to an impossibly small size and cause everything to crap out.
Mark

Constant change in SGA components up-down

hello,
we are developement database oracle 10gR2 on windows plateform
ASMM is on.
i am surprised to know that our smart oracle is doing a lot of shrink and grow on SGA components specially shared pool and db buffer cache
is it ok or some thing wrong?
i checked another development DB and found that it should be infrequent..
do i need to turn of the ASMM?
the out put from a query shown this
WHEN            COMPONENT                                                        OPER_TYPE     INITIAL_SIZE/1024      FINAL_SIZE/1024
May-16:19:53:17 DEFAULT buffer cache                                             STATIC        3031040                3014656
May-16:19:53:17 large pool                                                       GROW          0                      16384
May-16:19:53:17 DEFAULT buffer cache                                             INITIALIZING 3031040                3014656
May-16:19:53:17 ASM Buffer Cache                                                 STATIC        0                      0
May-16:19:53:17 DEFAULT 32K buffer cache                                         STATIC        0                      0
May-16:19:53:17 DEFAULT 16K buffer cache                                         STATIC        0                      0
May-16:19:53:17 DEFAULT 8K buffer cache                                          STATIC        0                      0
May-16:19:53:17 DEFAULT 4K buffer cache                                          STATIC        0                      0
May-16:19:53:17 DEFAULT 2K buffer cache                                          STATIC        0                      0
May-16:19:53:17 RECYCLE buffer cache                                             STATIC        0                      0
May-16:19:53:17 KEEP buffer cache                                                STATIC        0                      0
May-16:19:53:17 DEFAULT buffer cache                                             STATIC        0                      3014656
May-16:19:53:17 streams pool                                                     STATIC        0                      0
May-16:19:53:17 java pool                                                        STATIC        0                      16384
May-16:19:53:17 large pool                                                       STATIC        0                      16384
May-16:19:53:17 shared pool                                                      STATIC        0                      688128
May-16:20:30:59 shared pool                                                      GROW          688128                 704512
May-16:20:30:59 DEFAULT buffer cache                                             SHRINK        3014656                2998272
May-17:10:50:40 DEFAULT buffer cache                                             SHRINK        2998272                2981888
May-17:10:50:40 streams pool                                                     GROW          0                      16384
May-17:10:50:42 DEFAULT buffer cache                                             SHRINK        2981888                2965504
May-17:10:50:42 streams pool                                                     GROW          16384                  32768
May-17:11:04:38 shared pool                                                      GROW          704512                 737280
May-17:11:04:38 DEFAULT buffer cache                                             SHRINK        2965504                2932736
May-17:11:05:08 shared pool                                                      GROW          737280                 770048
May-17:11:05:08 DEFAULT buffer cache                                             SHRINK        2932736                2899968
May-17:11:06:01 DEFAULT buffer cache                                             SHRINK        2899968                2883584
May-17:11:06:01 shared pool                                                      GROW          770048                 786432
May-17:11:20:38 DEFAULT buffer cache                                             SHRINK        2883584                2850816
May-17:11:20:38 shared pool                                                      GROW          786432                 819200
May-28:15:24:06 DEFAULT buffer cache                                             SHRINK        2850816                2818048
May-28:15:24:06 shared pool any suggations/advice/help??
thank you

I saw this a lot on an highly OLTP system once at 10gR2. My SGA was thrashing wildly between buffer cache and shared pool due to a bug in AMM and it was causing performance impact (cursor S pin on X) for no apparent reason. This was particularly prevalent when I moved from a two to a three node cluster.
If you check out v$sga_resize_ops and see if you see a lot of thrashing (sometimes once every three seconds on one instance for 3 hours, then it'd switch to another instance), then my solution was to hardcode the various settings and disable AMM. However, in your case, you're resizing fairly irregularly - probably due to either an undersized component or workload changes. AMM is meant to do what you're describing - is it causing you any issue or is it something that you've noticed and are curious about?

Initial sizing of sga memory components.

Hi to all,
I want to know that how many granules be allocated to each sga components initially when we use automatic memory menagement. Let's say SGA _target is 1g. version 10.2.0
thnxs in advance.

The SGA comprises a number of memory components, which are pools of memory used to satisfy a particular class of memory allocation requests. Examples of memory components include the shared pool (used to allocate memory for SQL and PL/SQL execution), the java pool (used for java objects and other java execution memory), and the buffer cache (used for caching disk blocks). All SGA components allocate and deallocate space in units of granules. Oracle Database tracks SGA memory use in internal numbers of granules for each SGA component.
The memory for dynamic components in the SGA is allocated in the unit of granules. Granule size is determined by total SGA size. Generally speaking, on most platforms, if the total SGA size is equal to or less than 1 GB, then granule size is 4 MB. For SGAs larger than 1 GB, granule size is 16 MB. Some platform dependencies may arise. For example, on 32-bit Windows NT, the granule size is 8 MB for SGAs larger than 1 GB. Consult your operating system specific documentation for more details.
You can query the V$SGAINFO view to see the granule size that is being used by an instance. The same granule size is used for all components in the SGA.
If you specify a size for a component that is not a multiple of granule size, Oracle Database rounds the specified size up to the nearest multiple. For example, if the granule size is 4 MB and you specify DB_CACHE_SIZE as 10 MB, the database actually allocates 12 MB.

SOA-- Invoking OSB Service Getting Error :ORA-00084: global area must be PGA, SGA, or UGA

Hello Friends,
Really appreciate your help/inputs on the below Error Message encountered while running a Concurrent Program--using SOA:Same encountered in recently refreshed DEV instance, Can it be related to some Developement Instance Configuration related to SOA, as same working as expected in PROD.PLEASE ASSIST
Need your inputs on the Error Message we are getting which Invoking OSB Service.
"Error inside invoke_osb_service -> Error Code : -84Error Message :ORA-00084: global area must be PGA, SGA, or UGA "
Can you please review and confirm if the same encountered before or assist on the same:
XXFIN_AP_INVOICES_INT_IB_PKG.invoke_osb_service
-- Define the SOAP request according the the definition of the web service being called
l_soap_request :=
            '<?xml version = "1.0" encoding = "UTF-8"?>'
        || '<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:prox="http://OmnicareFinance/ProxyInput/">'
         ||   '<soapenv:Header/>'
         ||     '<soapenv:Body>'
         ||       '<prox:InboundProcess>'
         ||     '<Source_system>'||g_source_instance||'</Source_system>'
         ||     '<Run_mode>'||g_run_mode||'</Run_mode>'
         ||     '<Batch_key>'||g_batch_key||'</Batch_key>'
         ||     '<Request_id>'||g_request_id||'</Request_id>'
         ||     '<Invoice_Header_File_name>'||g_file_name||'</Invoice_Header_File_name>'
         ||     '<Invoice_Line_File_name>'||NULL||'</Invoice_Line_File_name>'
         ||     '<File_location>'||g_file_location||'</File_location>'
         ||       '</prox:InboundProcess>'
         ||     '</soapenv:Body>'
         ||   '</soapenv:Envelope>';
Oracle Apps Log File
-->Entering XXFIN_AP_INVOICES_INT_IB_PKG.invoke_osb_service
-->   = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
-->Response> status_code: "200"
-->Response> reason_phrase: "OK"
-->Response> http_version: "HTTP/1.1"
-->Response From OSB: <?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Header xmlns:prox="http://OmnicareFinance/ProxyInput/"/><soapenv:Body xmlns:prox="http://OmnicareFinance/ProxyInput/"><prox:InboundProcessResponse><status>E</status></prox:InboundProcessResponse></soapenv:Body></soapenv:Envelope>
-->OSB Response: E
-->Error inside invoke_osb_service -> Error Code : -84Error Message :ORA-00084: global area must be PGA, SGA, or UGA
-->   = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
-->Entering XXFIN_AP_INVOICES_INT_IB_PKG.capture_error_info
THANKS
ANKUR

Hi..
>
# symptom: ORA-00381: cannot use both new and old parameters for buffer cache size specification
# cause: Both db_block_buffers and db_cache_size parameters are defined in the init.ora (instance parameter file). The db_block_buffers parameter has been deprecated and has been maintained only for backward compatibility. The db_cache_size parameter is one of the size parameters which defines the size of the cache for buffers. These parameters cannot be combined. Setting this along with the Dynamic SGA parameters errors out.
>
For sga_target refer to [http://download.oracle.com/docs/cd/B19306_01/server.102/b14237/initparams193.htm#REFRN10256]
which quotes
>
SGA_TARGET specifies the total size of all SGA components. If SGA_TARGET is specified, then the following memory pools are automatically sized:
*Buffer cache (DB_CACHE_SIZE)
* Shared pool (SHARED_POOL_SIZE)
* Large pool (LARGE_POOL_SIZE)
* Java pool (JAVA_POOL_SIZE)
* Streams pool (STREAMS_POOL_SIZE)
If these automatically tuned memory pools are set to non-zero values, then those values are used as minimum levels by Automatic Shared Memory Management. You would set minimum values if an application component needs a minimum amount of memory to function properly.
>
So, the what ever the value are set for the parameter will act as minimum value when sga_target is set.
HTH
Anand

Where does a PL/SQL block run? PGA or SGA?

Hi all,
11g
I'm not familiar with the oracle memory structure, if I have a simple pl/sql block as below
DECLARE
v1 number;
BEGIN
v1:=100;
DBMS_OUTPUT.PUT_LINE(v1);
END;in my mind, even though it's a small block, when i execute it, it would also consume some memory, where does this memory come from, pga or sga?
in other words, when 'pl/sql engine' needs some memory, for example, for the local variables, where does this memory come from?
many thanks.

in my mind, even though it's a small block, when i execute it, it would also consume some memory, where does this memory come from, pga or sga?
in other words, when 'pl/sql engine' needs some memory, for example, for the local variables, where does this memory come from?SGA
The SGA comprises a number of memory components, which are pools of memory used to satisfy a particular class of memory allocation requests. Examples of memory components include the shared pool (used to allocate memory for SQL and PL/SQL execution), the java pool (used for java objects and other java execution memory), and the buffer cache (used for caching disk blocks). All SGA components allocate and deallocate space in units of granules. Oracle Database tracks SGA memory use in internal numbers of granules for each SGA component.
for any sort operations, hash joings, it uses PGA.
Read http://download.oracle.com/docs/cd/B19306_01/server.102/b14220/memory.htm

SGA + db_32k_cache_size

Happy New Year 2008
It's Holiday. But I'm still resolve some problem in my work.
I have some question on Oracle 10G, Because I don't understand SGA + db_xxk_cache_size any more.
Init... Parameters =>
sga_max_size big integer 7680M
sga_target big integer 7680M
db_32k_cache_size big integer 1504M
SQL> select * from v$sga;
NAME VALUE
Fixed Size 2085456
Variable Size 1107299760
Database Buffers 6928990208
Redo Buffers 14688256
SQL> select component, current_size from v$sga_dynamic_components;
COMPONENT CURRENT_SIZE
shared pool 1073741824
large pool 16777216
java pool 16777216
streams pool 0
DEFAULT buffer cache 5351931904
KEEP buffer cache 0
RECYCLE buffer cache 0
DEFAULT 2K buffer cache 0
DEFAULT 4K buffer cache 0
DEFAULT 8K buffer cache 0
DEFAULT 16K buffer cache 0
DEFAULT 32K buffer cache 1577058304
ASM Buffer Cache 0
SGA_TARGET = .... + db_32k_cache_size
7680M = .... + 1504M
I have understood like that. It true or not.

nK-cache values are not automatically managed by Oracle and settings for them are subtracted from the total SGA_TARGET before the remainder is distributed amongst the other, automatically managed, SGA components (like the default cache, shared, large and java pools).
If you say SGA_TARGET=8GB and DB_2K_CACHE_SIZE=1GB, then 7GB of memory is available for distribution amongst the automatically-managed SGA components.

Set SGA maximum size larget than it's component

Dear all,
I want to activate the DISM in Oracle 10g on Solaris container, therefore I need to set the parameter sga_max_size larger than it's component.
From my understanding, below are the sga components parameter and the current value on my system::
SHARED_POOL_SIZE (560M)
LARGE_POOL_SIZE (0)
JAVA_POOL_SIZE (32M)
DB_CACHE_SIZE (560M)
STREAMS_POOL_SIZE (0)
The thing is, my sga max size parameter (1168M) is already larger than above parameters.
Is there another sga component I've missed ? Plz advice. Thanks.

Hi,
SGA: The size is determined indirectly from the size of the contained memory areas.
1) Buffer pool: DB_BLOCK_BUFFERS (unit: blocks) or DB_CACHE_SIZE when you use the dynamic SGA
2) Shared pool: SHARED_POOL_SIZE
3) Java pool: JAVA_POOL_SIZE
4) Large pool: LARGE_POOL_SIZE
5) Streams pool (Oracle 10g or later): STREAMS_POOL_SIZE
6) Redo buffer: LOG_BUFFER
In addition, in the context of the dynamic SGA , you can define parameter
SGA_MAX_SIZE, which sets an upper limit for the total size of the SGA. In
general, you can only increase the size of parameters, such as DB_CACHE_SIZE
or SHARED_POOL_SIZE, up to the size defined by SGA_MAX_SIZE.
Thanks
Sunny

5 GB SGA on 8GB RAM HP Server 64Bit

Hi all
Recently three months we installed Oracle 10g Database on HP Server (having 4 XEON Processors) with Windows 2003 (64 Bit) OS and we have 8GB RAM.
We wished to have 5500M as the SGA Target but we could not configure more that 3800M on that machine as after that it would error and the database would not get start.
error messages would be like - Out of memory
OR
???? (not recollecting)
Now we are running with only 3500M as sga_target and not utilizing the full available RAM with us. Of course we are using in addition 1500M for pga_aggregate_target without any problem. Even if we increase pga_aggregate_target to 3000M there is no problem but that is not desired to us. We wish to increase sga_target.
We are getting excellent response timings on 3500M sga_target but as human nature would be , we wish to be more greedy and use the full available RAM with us i.e 8GB out of which we can safely use 7GB for Oracle instance. While deducting 1500M for pga_aggregate_target we would like to use 5500M for sga_target.
Any help is appreciated.
Suresh Bansal

Excerpt from oracle docs.
Benefits of Automatic Shared Memory Management
Automatic Shared Memory Management simplifies the configuration of the SGA. Before Oracle Database 10G, buffer cache, shared pool, java pool, and large pool need to be manually specified for the database. Under sizing can lead to poor performance and out-of-memory errors (ORA-4031), while over sizing can waste memory. This feature enables you to specify a total memory amount to be used for all SGA Components (buffer cache, shared pool, java pool, and large pool). The Oracle database periodically redistributes memory between these components according to workload requirements. Before Oracle Database 10G, the user did not have exact control over the total size of the SGA since memory was allocated by Oracle for the fixed SGA, and for other internal metadata allocations over and above the total size of the user specified SGA parameters. The new SGA size parameter SGA_TARGET now includes all the memory in the SGA, including all the automatically sized components, manually sized components, and any internal allocations during startup.
Configuring Automatic Shared Memory Management
Automatic Shared Memory Management can be configured by using the SGA_TARGET initialization parameter. If you specify a non-zero value for SGA_TARGET, the following four memory pools are automatically sized:
* Database buffer cache (Default pool)
* Shared pool
* Large pool
* Java pool
If you set SGA_TARGET to 0, Automatic Shared Memory Management is disabled. The default value of SGA_TARGET is 0.
The individual parameters used before Oracle 10G releases to specify the sizes of the automatically sized components have not been made obsolete. The initialization parameters that size these pools (DB_CACHE_SIZE, SHARED_POOL_SIZE, LARGE_POOL_SIZE, and JAVA_POOL_SIZE) are now referred to as auto-tuned SGA parameters.
The following buffers are now referred to as manually sized components:
* Log buffer
* Other buffer caches (KEEP/RECYCLE, other block sizes)
* Streams pool (new in Oracle Database 10g)
* Fixed SGA and other internal allocations
Note: STATISTICS_LEVEL must be set to TYPICAL (default) or ALL to use Automatic Shared Memory Management.
Jaffar

Oracle SGA Real Time Consumption Information(9i,10g and 11g)

Hello,
I need to prepare a comparative analysis report of SGA for an Oracle Production Instance
The analysis would show the pre-allocated memory to SGA components v/s real time consumption of memory by these SGA components. I need to do this for each of following components.
SGA itself
Fixed Size
Variable Size
Database Buffers
Redo Buffers
The pre-allocated memory to above SGA components can be obtained by querying v$sga. But from where do I get its real time(current) memory conusmption in Oracle Production environment.
In addition to above, i need the same information (pre-allocated and real time consumption) for following.
Keep buffer cache
Recycle buffer cache
Specific block size caches
Shared pool
Large pool
Java pool
streams pool
Which tables do I need to consider in order to derive 1)pre-allocated memory and 2)real time consumption for above mentioned SGA components
Please advice.
Thank you for your time in reading this post.
Thanks,
Ruchir

Hi,
Have a look at v$sgastat. Also, use statspack in 9i and AWR reports on 10g. Also, the size of the caches won't grow unless they are used. The parameters you have specified within the parameter file, like sga_target (10g onwards) and possibly the other pools if you have specified them, will show you what the caches can grow to.
For example, you could just log onto the DB and do show parameter sga_ or shared_pool and you will seee values for these. Also, it depends whether you are running in automatic memory management mode - where the sga_target parameter is set - or manual. 9i will be manual, but 10g could be auto. In manual case, 9i, check out the parameters individually.
Also, read the docs about the parameters shown and you will see what it says abotu them. There will be lots in the docs about performance tuning and monitoring of the instance. You might even learn some other interesting facts while reading through the docs...
Hope this helps,
Rob
http://www.ora00600.com

What are included in SGA?

SQL>SHOW SGA
Total System Global Area 840205000 bytes
Fixed Size 279240 bytes
Variable Size 520093696 bytes
Database Buffers 318767104 bytes
Redo Buffers 1064960 bytes
db_cache_size(or db_block_buffers) determine "Database Buffers "
log_buffer determine " Redo Buffers".
Could you tell me:
1) What initial parameters determine "Fixed Size "?
2) What initial parameters determine "Variable Size "?
Thanks

If you want to see detailed distribution of memory between sga components you can query V$SGASTAT;
[email protected]> select * from v$sgastat;
POOL NAME BYTES
fixed_sga 454040
buffer_cache 4194304
log_buffer 656384
shared pool errors 26720
shared pool KGK heap 3588
shared pool KQR M PO 551996
shared pool KQR S PO 127232
shared pool KQR S SO 5128
shared pool sessions 410720
shared pool sql area 6007480
shared pool 1M buffer 2098176
shared pool KGLS heap 1236464
shared pool parameters 30872
shared pool free memory 1101976
shared pool PL/SQL DIANA 748784
shared pool FileOpenBlock 695504
shared pool PL/SQL MPCODE 879748
shared pool library cache 4205580
shared pool miscellaneous 7396652
shared pool pl/sql source 92
shared pool MTTR advisory 8352
shared pool PLS non-lib hp 2820
shared pool joxs heap init 412
shared pool partitioning d 58300
shared pool partitioning i 6928
shared pool sim memory hea 21164
shared pool table definiti 224
shared pool trigger defini 2484
shared pool trigger inform 1600
shared pool trigger source 3404
shared pool type object de 27100
shared pool Checkpoint queue 282304
shared pool dictionary cache 2137216
shared pool ksm_file2sga region 370496
shared pool KSXR receive buffers 1033000
shared pool character set object 323328
shared pool FileIdentificatonBlock 323292
shared pool message pool freequeue 665792
shared pool KSXR pending messages que 841036
shared pool event statistics per sess 1918280
shared pool fixed allocation callback 188
Best Regards
Krystian Zieja / mob

Clarifications on SGA

Hello
Need some clarifications on SGA
1.When SGA is allocated and oracle started will it occupy the entire size of SGA?
2.Is there some tool or query to identify the actual consumption of SGA? If so pl help
Cheers,
Sunil

1.When SGA is allocated and oracle started will it occupy the entire size of SGA?The SGA is allocated when an instance starts and deallocated when the instance shuts down. Each instance that is started has its own SGA.
Oracle Database can set limits on how much virtual memory the database uses for the SGA. It can start instances with minimal memory and allow the instance to use more memory by expanding the memory allocated for SGA components, up to a maximum determined by the SGA_MAX_SIZE initialization parameter.
2.Is there some tool or query to identify the actual consumption of SGA? If so pl helpselect round(used.bytes /1024/1024 ,2) used_mb
,round(free.bytes /1024/1024 ,2) free_mb
,round(tot.bytes /1024/1024 ,2) total_mb
from (select sum(bytes) bytes
from v$sgastat
where name != 'free memory') used
,(select sum(bytes) bytes
from v$sgastat
where name = 'free memory') free
,(select sum(bytes) bytes
from v$sgastat) tot
v$SGA* views have current usages of SGA i.e. v$sga, v$sgastat,V$sga_dynamic_components,v$sgainfo, v$sga_current_resize_ops etc.
Regards
Girish Sharma

DOUBT REGARDING SGA

Hello,
can u plz explain the difference between SGA_TARGET and SGA_MAX_SIZE
parameters
if i specified sql>sho sga
Total System Global Area 1401424024 bytes
Fixed Size 456856 bytes
Variable Size 738197504 bytes
Database Buffers 629145600 bytes
Redo Buffers 33624064 bytes
in the above Total System Global Area indicates what? i mean this value
is equal to SGA_MAX_SIZE
can u plz suggest
Regards,

In an Oracle database, the SGA (System Global Area) is the part of the RAM used by the Oracle processes. This part of memory is shared by all Oracle processes. All necessary information necessary for the instance operation are present here.
In general, the SGA consists of the following:
•     Dictionary Cache: Information about data dictionary tables, such as information about account, datafile, segment, extent, table and privileges
•     Redo Log Buffer: Information about committed transactions that are not yet written to online redo log files.
•     Shared pool: The parsed cache of common used SQL statements and the data dictionary cache containing tables, views and triggers
•     JAVA pool: For parsing Java statements.
SGA_TARGET
============
The SGA_TARGET initialization parameter reflects the total size of the SGA and includes memory for the following components:
•     Fixed SGA and other internal allocations needed by the Oracle Database instance
•     The log buffer
•     The shared pool
•     The Java pool
•     The buffer cache
•     The keep and recycle buffer caches (if specified)
•     Nonstandard block size buffer caches (if specified)
•     The Streams pool
SGA_MAX_SIZE
=============
Oracle Database can set limits on how much virtual memory the database uses for the SGA. It can start instances with minimal memory and allow the instance to use more memory by expanding the memory allocated for SGA components, up to a maximum determined by the SGA_MAX_SIZE initialization parameter.
Note: For optimal performance in most systems, the entire SGA should fit in real memory.
Kindly read more about Oracle Memory Architecture
http://download.oracle.com/docs/cd/B19306_01/server.102/b14220/memory.htm#sthref1257
With Regards,

Ora-00604:error occurred at recursive SQL level 1 and Ora-04023

hi all
i am using oracle linux 5.5 and oracle Database 11g R2 while shutingdown the database i am getting
the following errors.
SQL> shutdown immediate;
Ora-00604:error occurred at recursive SQL level 1
Ora-04023: object select count(*) from reg$SQL>plz can anyone help me out?

Couple of questions related to this issue:
1.Is there anything in alert log. Post last 50 lines from alert log.
2.Is there any trace / log generated by Oracle ?
3.What is Memory_Target parameter value ?
4.What is value of statistics_level parameter ?
5.Did you perform any failed upgradation ?
6.Are there any invalid objects in database ?
Generally ORA-00604 is related to insufficient size of shared pool. Now, i am googling how to get a proper value of shared pool size ? I got that there is a view v$shared_pool_advice which will tell me the answer of this question. Ok, it means now question is how do i get the proper value of shared pool from v$shared_pool_advice; i mean how do i interpret this v$shared_pool_advice view ?
No problem docs are there to answer this question : (How i got this link ? Open a new page---http://tahiti.oracle.com---selected 11.2 docs--in the left hand sided there is a search text box i entered v$shared_pool_advice and i got couple of links)
http://download.oracle.com/docs/cd/E11882_01/server.112/e17110/dynviews_3037.htm#REFRN30239
I will read these links and now i will query this and DBA_HIST_SHARED_POOL_ADVICE views, interpret the values. Ok, but what about my original question i.e. ORA-00604 and 4023 ? If i am at this stage, understood all the values, it means now i can understand the meaning / sense of resizing of shared pool.
ALTER SYSTEM SET statistics_level=TYPICAL SCOPE=SPFILE;
You can monitor V$SGA_RESIZE_OPS to identify the range of values that Oracle is automatically resizing the DB_CACHE_SIZE and SHARED_POOL_SIZE components to. Then, pick an appropriate minimum value based on the range. There's no "magic formula". But V$SGA_RESIZE_OPS shows the sizes that Oracle has been automatically been resizing the SGA components to. The Buffer Cache Advisory section of the AWR report or V$DB_CACHE_ADVICE, V$SHARED_POOL_ADVICE, V$SGA_TARGET_ADVICE and DBA_HIST_SGA_TARGET_ADVICE are views that provide advisory information as well. Hemant @ SGA_MAX_SIZE and SGA_TARGET how to set minimum for pools
So, these are the baby steps if i ever gets ORA-00604 and ORA-04023 on my test database. Do all these and feel free to post the next doubt, i am sure you will get the correct answer.
Regards
Girish Sharma

SGA components

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