Standby Experiencing High "Standby Query SCN Advance" Waits.

刘泽宇

现象：
After moving the read only traffic to Standby and starting processing on Primary , "Standby Query SCN Advance" waits started to show up on the Standby database.

更改：
Moved the read only traffic to standby database.

原因：
This issue was reported in Unpublished Bug 33821145.

Fixed :- 19.15.0.0.220419DBRU

解决方法：
1.Apply the patch for 33821145

2.Determine the current value of the below parameter:-
Show parameter _Readable_standby_sync_timeout;
Show parameter _readable_standby_sync_interval;

3.Set the following values for these parameters
alter system set "_readable_standby_sync_timeout"=90 scope=spfile sid='*';

4.alter system set "_readable_standby_sync_interval"=300 scope=spfile sid='*';
Restart standby for these parameters to come into effect.