Oracle CPU_COUNT parameter
March 27, 2011 Leave a comment
If you want to view value of the parameter briefly you can also use show parameter command which searches the entered string with wildcard on both ends SQL> show parameter pool NAME TYPE VALUE ———————————— ———– ——– buffer_pool_keep string buffer_pool_recycle string global_context_pool_size string java_pool_size big integer 0 large_pool_size big integer 0 olap_page_pool_size big integer 0 shared_pool_reserved_size big integer 7759462 shared_pool_size big integer 0 streams_pool_size big integer 0 As you see the output above all parameters which include “pool” string in it are listed briefly. Setting Parameter for Instance You can set the parameter values with the command below
Alter system set parameter=value elements of the command; scope =BOTH/SPFILE/MEMORY indicates the scope of the parameter setting. both is the default behaviour. sid = SID/* if you are on RAC environment you can give SID or * for this element which indicate that the setting will effect only the given SID or all nodes in RAC configuration. comment= You can comment the change for future lookups. This comment can be viewed from UPDATE_COMMENT column of v$parameter view. deferred = this is the interesting element which i was aware of the existence till i read the book of Mr. Kyte. Indicates that the parameter change takes place for subsequent sessions only (not currently established sessions, including the one making the change). This element must be used for the parameters whose ISSYS_MODIFIABLE column in v$parameter view is deferred.
•When you want to change the parameter only for the running instance and not for the subsequent instance you can change it only in memory. ;
SQL> alter system set cpu_count=4 scope=MEMORY;
•When you want to change the parameter for subsequent instances only
SQL> alter system set cpu_count=4 scope=SPFILE;
•When you want to change the parameter for running and subsequent instances (if issys_modifiable is not false);
SQL> alter system set cpu_count=4 scope=BOTH;
This effects the parallelism of Orcale that can cause error “maximum number of sessions exceeded ORA-06512″, while installing SAP.