Interview at Hubspot

Recently I interviewed for a senior software engineer position at Hubspot. I had already cleared 2 coding rounds before being invited on-site and the feedback of the 2 rounds was also very positive. In the on-site , I had 3 rounds. The first was a DB design round. I felt I did pretty well in schema design, DB selection (based on the use case) and also writing queries. Post that , the interviewer asked me to not to use specific in-built functionalities in SQL query and try to come up with alternative. I tried but was only partially correct. Later with hint I was able to get the answer. My other 2 rounds (system design and the discussion with engineering director) both went smooth and great. It's been almost a week and I haven't heard back from the recruiter. How long does it take to hear back from the recruiter about the final feedback(I am an international applicant and would need VISA sponsorship)? Also , can I be rejected as I was not able to readily come up with solution in DB design round?