Most webhosting companies including Bluehost do not allow users to access SSH with their shared hosting accounts.
However, Siteground allows SSH access even for the shared hosting plans.
Yesterday, I had to import a big DB file to the existing database. I requested the support team to import the DB for me. They did it in no time.
They [Advanced tech team] will give you a response within 10minutes with detailed answer and a solution.
They actually processed it within 10 minutes. Siteground's support is very satisfacgtory to me.
However, it's also possible to import it by yourself if you access SSH. Please refer to the following documents for details on how to log in to your SiteGround shared account via SSH using PuTTY.
I think Siteground will be a good choice if you want stable and high-performance web-hosting services.