Asynchronous client database creation.
Module does not work on 9.0 because connector ain't ported for 9.0 for this time.
Get connector module https://github.com/OCA/connector/tree/8.0
Optionaly you may test connector module using this module: https://github.com/OCA/connector-interfaces/tree/8.0/test_base_import_async
For example try to export/import asyncronous way some contacts.
Install this module.
Mark "asynchronous" checkbox when creating new client database from saas plan.
You can look up database creation jobs in Connector->Jobs. If job is done new base is finished.