All-in-One WP Migration plugin uses MySQL/MariaDB to retrieve and store WordPress data (posts, pages, comments, users, and more). On severely limited hosting plans, it is possible to encounter a database limit set by the hosting provider.
Here is a list of all the limits that can be reached when using All-in-One WP Migration:
The number of queries that an account can issue per hour.
The number of updates that an account can issue per hour.
The number of times an account can connect to the server per hour.
The number of simultaneous connections allowed.
If you encounter such a limit, contact your hosting provider and ask if they can increase it.