How to change SGA and PGA in 10g r2 RAC

Question

Hi,
How to change SGA and PGA in 10g r2 RAC, its Linux.

Answer 1

Hi,
Here is the way i followed to change SGA and PGA in RAC.
Action Plan to change the memory parameter in the production environment(5/21/2010)
Note:
=====
Practice should be done in the DEV/TST environment before moving to Production;
Although the procedure could be applied in the testing environment the changing values
used in the testing environment should be modified since RAM number are not the
same between the testing servers and production servers.
1.     Make changes to these two parameters in one of
     the prod instance, e.g. PROD1
     ====================================================
     login as sysdba on sqlplus
Change :
alter system set sga_target=28G scope=spfile sid='*';
Change :
alter system set pga_aggregate_target=4G scope =spfile sid='*';
     sql>alter system set pga_aggregate_target=4G scope=both;
     sql>show parameter pga_aggregate_target;      
          -- should see the altered number on both instances
Change:
sql>alter system set sga_max_size=28G scope=spfile sid='*';
sql>alter system set sga_max_size=28G scope=spfile ;
sql>alter system set sga_target=28G scope=spfile;
3.     shutdown database PROD (two instances should be shut down)
     $>srvctl stop database -d PROD
     $>. /$ORA_CRS_HOME/bin/crs_stat -- to check for the database status
4.     bring up database PROD (two instance should be brought up)
     $>srvctl START database -d PROD
     $>. /$ORA_CRS_HOME/bin/crs_stat -- to check for the database status
     login into both instances as sysdba to check
     sql>show parameter pga_aggregate_target
     sql>show parameter sga_max_size
          -- should see the altered number still there in both instances
          -- from step 1
     -- After confirming above two parameters are altered on both instances,
     -- then issue the syntax below in one instance
5)     check everything is ok