I am of the opinion that that creating a new sql server instance on top of your could instance will slow it down further instead users can use the cloud instance directly and do a self service BI.
Hi Bharat ,
You mean to use cloud instance through tableau right ?
Using a on premise sql server instance on top of cloud instance would be wrong instead use the cloud instance in tableau directly.
This would save lot of time and money to the business client.
Hope I am clear.