Hi,
Stopping DB deployment is not recommended but instead when the execution is taking more time than the usual, you can check the blocking sessions on the database. You can use PLSQL to check the blocking sessions caused by other DB jobs and if you can validate that they can be killed at that moment, you can safety kill them to give priority to your installer session. Be cautious, your installer session & other important DB jobs will be listed there as well so do not kill them. 

Also, if you want to run only the middle tier, you can use “--set action=mtinstaller” in the installer.cmd
https://docs.ifs.com/techdocs/22r2/070_remote_deploy/010_installing_fresh_system/200_installing_ifs_cloud/035_ifs_cloud_ifsinstaller/020_installer_actions/

Regards,
Nishanth