About _external_scn_rejection_threshold_hours parameters and SCN headroom patch issues on Oracle DB 11GR2 release

About _external_scn_rejection_threshold_hours parameters and SCN headroom patch issues on Oracle DB 11GR2 release

From:
Installing, executing and interpreting output from the "Scnhealthcheck.sql" script (document ID 1393363.1)

1th:

In addition to the above result the script output could advise to set the hidden parameter "_external_scn_rejection_threshol D_hours "on some Oracle versions. The following text gives more information on setting this parameter:

Set _external_scn_rejection_threshold_hours=24 after apply
Oracle recommends setting this parameter to the value of 10g and 11.1 releases-it does not need to is set in 11.2 or Later releases. The parameter is a static and so must being set in the Init.ora or spfile used to start the instance.
eg
In Init.ora:
# Set threshold on Dd/mon/yyyy-see MOS Document 1393363.1
_external_scn_rejection_threshold_hours = 24

In the SPFile:
Alter system set "_external_scn_rejection_threshold_hours" = 24
Comment= ' Set threshold on Dd/mon/yyyy-see MOS Document 1393363.1 '
Scope=spfile;

As can be seen from the above, on the 11.2 and later versions, there is no need to set the _external_scn_rejection_threshold_hours parameter.

2nd:

Please note that there is no SCN hardening fixes for the following versions. The recommendation for these versions are to upgrade to a newer release: all versions up to and  including 9.2.0.7  V Ersions 10.1.0.2 to 10.1.0.4 inclusive  Versions 10.2.0.1 and 10.2.0.2  version 11.1.0.6  version 11.2.0.1

As can be seen from this sentence: The above version of the Oracle database software does not repair the SCN headroom patch. Please upgrade to an updated version. This is a tough trick.

Versions 11.2.0.4 and 12.1.0.1 onwards already include the main SCN fixes but the "Scnhealthcheck" script described above Can still is used on those releases to check the current headroom.

It can be seen from this sentence that, in 11.2.0.4 and its 12.1.0.1 version, the issue of SCN has been fixed (fixes), and it is clear that 11.2.0.4 and its 12.1.0.1 version of the program have fixed the SCN headroom issue.