Poor performance with changelist submitting and approving

I'm using PowerDesigner 16.6. Repository is set on Oracle DBMS with Proxy. Physical model has 900 tables. When adding one column to the one table:

• checking in the changes takes 30 sec to display the Merge changes to Repository Document window and then 30 sec to move the changes to repo,
• using the changelist with the same changes takes 2-2.5 minutes to display the Merge changes to Repository Document window and then 30 seconds to move changes to the changelist,
• Approving the changelist take 1 minute to show Integrate Changes to Target Branch window and 3-4 min to commit changes to the model in the repository.

Are this times normal? It seems quite slow.