Smartsheet has a max capacity of halding 20000 rows.I am worried does it will not be able to handle millions records it we connect it to a connector..?
Although the limit of rows in a Sheet is 20,000, you may want to create multiple sheets with a more specific criteria E.G Department, Location.
You could also then use Reports to collate relevant data from multiple sheets. See more on this here: https://help.smartsheet.com/articles/522214-creating-reports
In addition to this, you may want to reach out to our Consulting Team. This is where you detail your business requirements, we create a solution and then provide it back to you with training on how it works. Please see the following article for more information: https://www.smartsheet.com/services/consulting
Let me know if you have any questions!