VLDB 2021: Visa Information
SIGMOD and VLDB have an agreement that if an author cannot attend the conference due to visa issue, the author may present the paper at the next upcoming SIGMOD. The author may also present the paper as rollover paper at the VLDB conference in the following year.
There is an option to ask for visa letter while registering for in-person participation, as indicated in the image below. If an invitation letter is required, Kuoni will take care of the request.