Systems and methods of maintaining a horizontally scaled database based on data ownership for a cloud-based platform (e.g., cloud-based collaboration and/or storage platform/service) are disclosed. The system database comprises multiple shard databases, and all files and folders owned by a user are stored on a single shard database. When a user transfers ownership of a file and/or a folder to a second user, the transferred file and/or folder is stored on the shard database that stores all of the data for the second user.