View hidden parameters
SELECT x.ksppinm name,
y.ksppstvl value,
y.ksppstdf isdefault,
decode(bitand(y.ksppstvf,7),1,'MODIFIED',4,'SYSTEM_MOD','FALSE') ismod,
decode(bitand(y.ksppstvf,2),2,'TRUE','FALSE') isadj
FROM
sys.x$ksppi x,
sys.x$ksppcv y
WHERE
x.inst_id = userenv('Instance') AND
y.inst_id = userenv('Instance') AND
x.indx = y.indx
--and x.ksppinm ='_external_scn_rejection_threshold_hours'
order BY translate(x.ksppinm, ' _', ' ');
Modify the implicit parameter method:
Here are a modified DRM (with a bug, easily lead to the collapse of RAC instance) Examples of implicit parameter. Various modifications implied different parameters, in particular the need to view documents
The method can be restarted to change a :( Method)
SQL> alter system set “_gc_policy_time”=0 scope=spfile sid=’*’;
System altered.
SQL> alter system set “_gc_undo_affinity”=false scope=spfile sid=’*’;
System altered.
After he finished, you need to restart to take effect, see
Method 2 (not restart)
If you temporarily unable to restart the instance, you can use the following command to "de facto" disable DRM :( following two parameters can be dynamically adjusted)
alter system set “_gc_affinity_limit”=10000000;
alter system set “_gc_affinity_minimum”=10000000;