Posted to SAP and got below reply.
The report RSSGOSHIRE offers you the following
functions:
1. The object history can be activated or deactivated across the whole
system.
If the object history is activated for the whole system, you can
deactivate it for individual users with the parameter SOBJHIST = 'X'.
2. You can delete the entire data of the object history.
This removes all data from the table SGOSHIST.
3. You can reorganize the entire data of the object history.
In a reorganization, the entries of each user in table SGOSHIST are
reduced to 20 entries for each application object. This reorganization
is done automatically when a user displays the object history.