SGA resize

Can we resize SGA after setting SGA_MAX_SIZE to some number.
what parameters will be considered whule allocating this size.

I hope you are talking about dynamic SGA feature of 9i. Following link would help you in this regards.
http://www.dbazine.com/burleson1.html

Similar Messages

  • Reduced SGA_TARGET, but SGA size not changing?

    I reduced the sga_taget from 1536M to 512M:
    alter system set sga_target = 500M scope = memory;
    System altered.
    select VERSION from v$instance;
    VERSION
    10.2.0.3.0
    show parameter sga
    NAME TYPE VALUE
    lock_sga boolean FALSE
    pre_page_sga boolean FALSE
    sga_max_size big integer 1536M
    sga_target big integer 512M
    But the real memory still showing the original value
    show sga
    Total System Global Area 1610612736 bytes
    Fixed Size 2030456 bytes
    Variable Size 1509950600 bytes
    Database Buffers 83886080 bytes
    Redo Buffers 14745600 bytes
    why is that while it's a dynamic parameter?
    Thanks a lot for any help.
    Edited by: user10484253 on May 13, 2011 8:36 AM
    Edited by: user10484253 on May 13, 2011 8:39 AM
    Edited by: user10484253 on May 13, 2011 8:41 AM

    I would suggest you to check v$sgastat to find out the exact SGA memory you are using currently instead of using "SHOW SGA" when when you set SGA_MAX_SIZE & SGA_TARGET initialization parameters.
    Below is a sample output from one of my test dbs. As you can see below my SGA size is only 1GB.
    SHOW SGA shows 2GB thats because I have set SGA_MAX_SIZE to 2gb ( which only means that I can grow my sga up till 2 gig , it may not be my current sga size).
    you can try increasing or decreasing SGA_TARGET and check memory usage on OS level to see the difference.
    SQL>show parameter sga
    NAME                                 TYPE        VALUE
    lock_sga                             boolean     FALSE
    pre_page_sga                         boolean     FALSE
    sga_max_size                         big integer 2000M
    sga_target                           big integer 1008M
    SQL>show sga
    Total System Global Area 2087780352 bytes
    Fixed Size                  2155336 bytes
    Variable Size            1744833720 bytes
    Database Buffers          318767104 bytes
    Redo Buffers               22024192 bytes
    SQL>select name, round(sum(mb),1) mb
      2        from (
      3      select case when name = 'buffer_cache' then 'db_cache_size'
      4                  when name = 'log_buffer'   then 'log_buffer'
      5                  else pool
      6              end name,
      7              bytes/1024/1024 mb
      8                   from v$sgastat
      9           )group by name
    10  /
    NAME                  MB
    db_cache_size        304
    java pool            128
    large pool            16
    log_buffer            21
    shared pool          528
                         2.1
    6 rows selected.
    SQL> -- V$SGA_DYNAMIC_FREE_MEMORY: Information about the amount of SGA memory available for future dynamic SGA resize operations.
    SQL>select * from V$SGA_DYNAMIC_FREE_MEMORY;
    CURRENT_SIZE
      1040187392- Krishna

  • Overheads of  Automatic SGA.

    Hello
    What are peformance overheads of turning on Automatic SGA(SGA_TARGET > 0 ) feature in 10gR2(10.2.0.3)? We are migrating our OLAP database to 10g on Linux and would like to know the impacts before we do that..
    How frequently Oracle performs the resize operations and how much latencies it introduces to the response time?
    How do you monitor the latencies introduced by SGA resize operations? i.e. what event user session will wait ( if waits ) if resize operations are under progress?
    How buggy/stable this feature is ?

    user4529833 wrote:
    Hello
    What are peformance overheads of turning on Automatic SGA(SGA_TARGET > 0 ) feature in 10gR2(10.2.0.3)? We are migrating our OLAP database to 10g on Linux and would like to know the impacts before we do that..
    How frequently Oracle performs the resize operations and how much latencies it introduces to the response time?
    How do you monitor the latencies introduced by SGA resize operations? i.e. what event user session will wait ( if waits ) if resize operations are under progress?
    How buggy/stable this feature is ?As with all self-managing systems, there is an overhead. It is in two specific areas - monitoring and logging of the load and adjusting the parameters dynamically. You do pose an interesting question as to which metrics are available to monitor the management process. I have not dug into it, so I can not answer the question - yet. I'm just responding to highlight that it has an impact at other times as well.
    Flip side - what are the performance overheads and performance losses associated with the DBA tuning (or, more likely not tuning) the SGA & PGA manually per the various workflow requirements. This is the case that the auto tuning was likely designed to tackle.
    I highly doubt that the feature will be better than a crack DBA team adjusting the pools manually based on real and known workload. But I don't run into many situations where an entire crack DBA team can be assigned to proactively manage DB performance 24x7. (Thus, the feature becomes useful in spite of overhead.)

  • AMM Shrink and grow question

    Hi,
    i've 11.2 Database.
    I know that using AMM, Oracle manages sga and pga together.
    But why shink and grow (sga pools) operation impact only shared and buffer and not also the pga?
    An example, I've 5Gb of AMM, looking AWR, Oracle set shared pool to about 1,9Gb, buffer to 1,1Gb (sga target around 3,3Gb) and the results to PGA.
    Looking Memory Dynamic Components in AWR, i see that shrink/grow operation uses only shared and buffer pool and not the PGA that is not used.
    Why this?
    Thanks.

    Mr.D. wrote:
    Hi,
    i've 11.2 Database.
    I know that using AMM, Oracle manages sga and pga together.
    But why shink and grow (sga pools) operation impact only shared and buffer and not also the pga?
    An example, I've 5Gb of AMM, looking AWR, Oracle set shared pool to about 1,9Gb, buffer to 1,1Gb (sga target around 3,3Gb) and the results to PGA.
    Looking Memory Dynamic Components in AWR, i see that shrink/grow operation uses only shared and buffer pool and not the PGA that is not used.
    Why this?
    Thanks.What I understood from your question is that you dont see reallocation of PGA as you see in SGA resizable components.
    [url http://docs.oracle.com/cd/B28359_01/server.111/b28310/memory003.htm] this  describes how the PGA is allocated.
    Unless there is pressure on oracle to release the memory from PGA to allocate to SGA or vice versa you will not see the change in memory allocation for PGA

  • Alter system set shared_pool_size extremely slow.

    I am trying to increase my shared_pool_size from 60m to 200m by simply typing alter system set shared_pool_size=200m;
    I did alter system flush shared_pool; before to clear out the current shared_pool.
    I'm on 9i and my SGA_MAX_SIZE is 3g and I have plenty room to grow.
    show sga
    Total System Global Area 3222769016 bytes
    Fixed Size 744824 bytes
    Variable Size 2382364672 bytes
    Database Buffers 838860800 bytes
    Redo Buffers 798720 bytes
    My event in v$session_wait is background parameter adjustment.
    Any help would be appreciated. I know that I can bounce the server and let it read it from the init.ora. However, I'm trying to fix some current 4031s in my shared pool. The flush did fix them temporarily.

    Are you sure your instance was in the state you thought it was ? This is what you reported from show sga:
    Total System Global Area  3222769016 bytes
    Fixed Size                    744824 bytes
    Variable Size             2382364672 bytes
    Database Buffers           838860800 bytes
    Redo Buffers                  798720 bytesYou say your shared_pool_size is 60M and you want to grow it to 200M, but the Variable Size in the output above suggests that your shared pool had already grown to about 2.3 GB, so your command would have been trying to shrink it quite dramatically. (And 9i isn't very good at shrinking the shared pool because of the problems of pinned and "KEEP"ed objects in the library cache.
    Things to check (from another session):
    v$sga_current_resize_ops to see if your resize operation is still running, and what it's trying to do.
    v$sga_resize_ops to see i f your resize operation completed some time ago - leaving your session stuck somewhere else. (There's a convenient query I wrote against this view published here: http://jonathanlewis.wordpress.com/2007/04/16/sga-resizing/ )
    v$session_wait (for the resize session) to see if the session is waiting or working
    v$sesstat (for the resize session) to see if it gives you any clues about current activity
    Regards
    Jonathan Lewis
    http://jonathanlewis.wordpress.com
    http://www.jlcomp.demon.co.uk

  • Single record insert performance problems

    Hi,
    we have on production environment a Java based application that makes aprox 40.000 single record Inserts per hour into a table.
    We ha traced the performance of this Insert and the medium time is 3ms, that is ok. Our Java architecture is based in Websphere Application Server and we access to Oracle 10g through a WAS datasource.
    But we have detected that 3 or 4 times a day, during aprox 30 seconds, the Java service is not able to make any insertion in that table. And suddenly it makes all the "queued inserts" in only 1 second. That "pause" in the insertion cause problems of navigation because is the top layer there is a web application.
    We are sure that is not a problem with the WAS or the Java code. We are sure that is a problem with the Oracle configuration, or some tunning action for this kind of applications that we don´t know. We first thought it could be a problem with a sequence field in the table. Also, a problem when occurs the change of the redo log. But we've checked it with our DBA and this is not the problem.
    Has anybody any idea of what could be the origin of this extrange behaviour?
    Thanks a lot in advance.
    Jose.

    There are a couple of things you'd need to look at to diagnose this - As Joe says it's not really a JDBC issue from what we know.
    I've seen issues with Oracle's automatic SGA resizing causing sporadic latency in OLTP systems. Another suspect would be log file sync wait events, which are associated with commits. Don't discount the impact of well meaning people using tools like TOAD to query the DB - they can sometimes cause more harm than good.
    Right now I'd suggest you run AWR at 10 minute intervals and compare reports from when you had your problem with a time when you didn't.

  • Comparison Mechanism of AMM

    Hello !
    Please explain
    what is the key difference between processes/mechanisms the GROWING/SHRINKING of pools (sga_target<>0)
    and clearing of granules (set sga_max_size and sga_target=0) ?
    Thanks and regards,
    Pavel
    Edited by: Pavel on May 10, 2012 11:08 PM
    Edited by: Pavel on May 10, 2012 11:08 PM

    Growing and shrinking of pool is based on requirement.
    in 10g we've SGA_target and SGA resize operation detail is available in below view.
    V$SGA_RESIZE_OPS displays information about the last 400 completed SGA resize operations. This does not include in-progress operations. All sizes are expressed in bytes.
    in 11g we've memory target parameter for SGA and PGA.
    V$MEMORY_CURRENT_RESIZE_OPS displays information about memory resize operations (both automatic and manual) which are currently in progress. An operation can be a grow or a shrink of a dynamic memory component.

  • Resizing SGA in 9i

    Hi,
    How to resize the SGA memory size in 9i. What are all the parameter needs to be change for this?
    Right now, DB is running in pfile. Having sga_max_size = 6G.
    Thanks in advance!!

    There is plenty of info in the fine manuals
    http://download.oracle.com/docs/cd/B10501_01/server.920/a96521/create.htm#998095
    http://download.oracle.com/docs/cd/B10501_01/server.920/a96524/c08memor.htm#19799
    http://download.oracle.com/docs/cd/B10501_01/server.920/a96533/memory.htm#38371
    and more !
    HTH
    Srini

  • Resizing Shared Pool or SGA Target??

    I need to resize my shared pool to 512M
    I am using 10g Enterprise Edition. 10.1.0.4 on windows 2003
    Do i need to bounce the db or i can do this task using alter system command w/o shutting down the db??
    I believe i will hv to resize the sga_maz_size aswell...
    However is it true that if i set the sga_target.. everything will be taken care of.
    I am trying to upgrade Oracle EM Grid Control from the basic 10.2.0.2 to 10.2.0.5
    According to the read me file, the upgrade patch requires shared pool to be a minimum of 512M.
    Note : this is a development server.. hence no applications, no testing is done on it now.. as of now for the smooth install and upgrade.. please help me with correct parameter and values to do this task.
    Kind regards

    Please delete one of the posts.. double posting.

  • Resizing SGA

    Hi,
    I am wokring on 10.2.0.4 and Hp-UX
    right now i am using SGA_MAX_SIZE= XX MB and SGA_TARGET=XX MB and using kks_use_mutex_pin=False parameter .
    now i want to set following values
    SGA_MAX_SIZE= Not set
    SGA_TARGET = Not set
    Remove kks_use_mutex_pin paraneter ..
    I m using spfile ...
    how can i do this ...
    alter system set SGA_MAX_SIZE= NULL/ ...? scope=both
    or how ...

    oradba11 wrote:
    Ok..
    but in pfile what value i need to set for disable/No value SGA_MAX_SIZE parameter ...
    i want to remove kks_use_mutex_pin parameter alos ...First why you want disable shared memory management?,oracle recommend that use ASMM.In additionally if you want using manual shared memory management then you have set sga_max_size and sga_target=0,and you have to set db_buffer_cahche/shared_pool/log_buffer initialization parameter ,you need manually manage these.If you use pfile then edit it then change these else you use spfile then change alter system set ... scope=spfile and restart database

  • Tuning of SGA on Oracle 8.0.5 and AIX 4.3.3

    Hi folks,
    I have an AIX box running AIX 4.3.3 and Oracle 8.0.5.2.0. The original SGA settings are as follows:
    shared_pool_size = 150000000
    sort_area_size = 1024876
    db_block_buffer = 126102
    The SGA size then is:
    Total System Global Area 1838467232 bytes
    Fixed Size 47264 bytes
    Variable Size 803287040 bytes
    Database Buffers 1033027584 bytes
    Redo Buffers 2105344 bytes
    I changed the SGA settings to the following:
    shared_pool_size = 768000000
    sort_area_size = 512000000
    The SGA size is now:
    Total System Global Area 2227943584 bytes
    Fixed Size 47264 bytes
    Variable Size 214097920 bytes
    Database Buffers 2013265920 bytes
    Redo Buffers 532480 bytes
    After this change was done, the system ran but the users had some problems running reports in JDEOneWorld.
    I then downsize the SGA settings and altered the db_block_buffer to improve buffer cache hits with these settings:
    db_block_buffers = 245760
    shared_pool_size = 200000000
    sort_area_size = 1048576
    On restarting the database with the new values, I noted that the SGA size remained unchanged as below:
    Total System Global Area 2278475936 bytes
    Fixed Size 47264 bytes
    Variable Size 264105984 bytes
    Database Buffers 2013265920 bytes
    Redo Buffers 1056768 bytes
    I tried to increase the size of db_block_buffers to 327680 but encountered ORA-27123 when trying to startup the database. I did some searches in metalink and found an article saying that the SGA size cannot exceed 2GB on AIX platforms. (Doc ID: 114934.1). Therefore I resize the db_block_buffers back to 245760.
    What puzzles me is why the SGA size does not reflect my latest init.ora settings? Does anyone have any idea on how I can get the SGA to reflect the updated values in the init.ora file?

    I did a find and here are the files I got:
    278529 12 -rw-r--r-- 1 oracle dba 8332 May 12 1998 /u01/app/oracle/product/805/dbs/init.ora
    278531 0 lrwxrwxrwx 1 oracle dba 43 Apr 14 2001 /u01/app/oracle/product/805/dbs/initklb.ora -> /u01/app/oracle/admin/klb/pfile/initklb.ora
    278532 0 lrwxrwxrwx 1 oracle dba 45 Apr 14 2001 /u01/app/oracle/product/805/dbs/initklb_0.ora -> /u01/app/oracle/admin/klb/pfile/initklb_0.ora
    49154 8 -rw-r--r-- 1 oracle dba 4657 Sep 7 2000 /u01/app/oracle/product/orig_db/initklb.ora
    49155 8 -rw-r--r-- 1 oracle dba 4657 Jul 27 2000 /u01/app/oracle/product/orig_db/initklb_0.ora
    151553 4 -rw-r--r-- 1 oracle dba 2985 Aug 4 2006 /u01/app/oracle/product/luz/pfile/initklb.ora
    49161 8 -rw-r--r-- 1 oracle dba 4118 Oct 11 11:22 /u01/app/oracle/admin/klb/pfile/initklb.ora
    135169 4 -rw-r--r-- 1 oracle dba 2896 Aug 4 2006 /u01/app/oracle/admin/klb/pfile/backup/initklb.ora
    49168 8 -rw-r--r-- 1 root dba 4687 Jul 21 2001 /u01/app/oracle/admin/klb/pfile/archive/initklb1.ora
    49162 8 -rw-r--r-- 1 oracle dba 4657 Dec 23 1999 /u01/app/oracle/admin/klb/pfile/archive/initklb_0.ora
    The instance name is KLB so the applicable files are:
    278531 0 lrwxrwxrwx 1 oracle dba 43 Apr 14 2001 /u01/app/oracle/product/805/dbs/initklb.ora -> /u01/app/oracle/admin/klb/pfile/initklb.ora
    278532 0 lrwxrwxrwx 1 oracle dba 45 Apr 14 2001 /u01/app/oracle/product/805/dbs/initklb_0.ora -> /u01/app/oracle/admin/klb/pfile/initklb_0.ora
    49154 8 -rw-r--r-- 1 oracle dba 4657 Sep 7 2000 /u01/app/oracle/product/orig_db/initklb.ora
    49155 8 -rw-r--r-- 1 oracle dba 4657 Jul 27 2000 /u01/app/oracle/product/orig_db/initklb_0.ora
    151553 4 -rw-r--r-- 1 oracle dba 2985 Aug 4 2006 /u01/app/oracle/product/luz/pfile/initklb.ora
    49161 8 -rw-r--r-- 1 oracle dba 4118 Oct 11 11:22 /u01/app/oracle/admin/klb/pfile/initklb.ora
    135169 4 -rw-r--r-- 1 oracle dba 2896 Aug 4 2006 /u01/app/oracle/admin/klb/pfile/backup/initklb.ora
    49168 8 -rw-r--r-- 1 root dba 4687 Jul 21 2001 /u01/app/oracle/admin/klb/pfile/archive/initklb1.ora
    49162 8 -rw-r--r-- 1 oracle dba 4657 Dec 23 1999 /u01/app/oracle/admin/klb/pfile/archive/initklb_0.ora
    Now, exclude the files in the product, backup and archive directories (the pfile should be in the pfile directory), and that leaves us with:
    49161 8 -rw-r--r-- 1 oracle dba 4118 Oct 11 11:22 /u01/app/oracle/admin/klb/pfile/initklb.ora
    (Which is the file that I edited)
    As I mentioned previously, my client is not prepared to perform an upgrade on both Oracle and AIX. As much as I would like to have them upgrade to the latest versions, it is just not possible.
    Oracle 8.0.5 does not have spfiles, so there is no way for me to edit a spfile unless this is one of those undocumented tricks floating around.

  • Problem in sizing sga

    Dear All,
    We are using Oracle 10g R2 on windows 2003.Our sga_max_size=2000m and sga_target=800m.We have enabled ASM.
    I got an alert message in enterprize manger which says virtual memory paging is happening and its impact is 100%.
    Now,Is this problem related to SGA?Do i have to resize my sga_max_size ?
    We have 4gb RAM 460 gb hard disk what would be the ideal size for sga?
    Regards,
    Kris

    For guidelines over SGA & memory, refer discussion here...
    Re: windows 32bit sga and pga limits
    But actual sizing of SGA depends on your application needs. If it needs more SGA, it does. You might need to add more RAM to your server to cope up with existing workload for a given number of users.

  • ORACLE SGA size

    We bought a server for oracle data warehousing which has got 200GB RAM. Can I set set my SGA_TARGET to 100GB. Is it true the more SGA size result in better performance.
    Thaks
    jeevan

    Hi Jeevan,
    I would not set sga_target, it can cause RAM thrashing . . .
    In an article titled Automatic Shared Memory Management we see:
    http://www.oracle.com/technology/pub/articles/10gdba/week17_10gdba.html
    Some pools in SGA are not subject to dynamic resizing, and must be specified explicitly. Notable among them are the buffer pools for nonstandard block sizes and the non-default ones for KEEP or RECYCLE. If your database has a block size of 8K, and you want to configure 2K, 4K, 16K, and 32K block-size pools, you must set them manually.
    Their sizes will remain constant; they will not shrink or expand based on load. You should consider this factor when using multiple-size buffer, KEEP, and RECYCLE pools.
    In addition, log buffer is not subject to the memory adjustment—the value set in the parameter log_buffer is constant, regardless of the workload. ( In 10g, a new type of pool can also be defined in the SGA: Streams pool, set with parameter streams_pool_size. This pool is also not subject to automatic memory tuning.)
    Is it true the more SGA size result in better performance. Yes, but it may not be much, or it could be alot! It depends.
    On a dedicated server, your goal is to allocate all the RAM, without causing swapping. I have my notes here:
    http://www.dba-oracle.com/art_dbazine_ram.htm
    Hope this helps . . .
    Donald K. Burleson
    Oracle Press author
    Author of "Oracle Tuning: The Definitive Reference"
    http://www.rampant-books.com/book_2005_1_awr_proactive_tuning.htm

  • (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....

  • ASMM - sga dynamic components and standby

    Are SGA dynamic modifications "transferred" from the primary to the standby?
    i.e: if __shared_pool is resized in primary will this also trigger standby?
    Trying to determine if dynamic pools may somehow end up being different upon switchover/failover or if it's possible that upon switchover standby's dynamic shared_pool size results smaller than that of former primary

    Absolutely, yet there are some things DG broker does upon switch over. Was wondering if somehow standby would be "updated" upon switcher...
    But then again, it's SGA as a hole may be smaller to begin with...
    Were you to tell if the following is true or false:
    "After activation standby database may have a SGA configuration different than that of primary"
    what would you say?
    Hole intention here is to determine whether after a switch over it's possible to start getting ORA-04031 on account of dynamic pools being different
    and oracle struggling to re-size them...
    Suppose we have a 6Gb SGA... primary has been working full steam for say 2 months and dynamic pools are set by oracle in the following way:
    shared_pool...3Gb
    cache...3Gb
    Now if standby has not acknowledged those dynamic changes, it may be using values of it's own... maybe a larger cache... say
    shared_pool...1Gb
    cache...5Gb
    Now we switch-over and if sga settings are not "synced", then new primary will have 2Gb less of shared pool...
    Application kicks in, shared pool runs low... Oracle will have to move 1 or 2Gbs from cache to shared pool, this will cause serious latching and most likely ORA-04031
    so is that likely to happen?

Maybe you are looking for