To establish an infrastructure for querying and sorting planetary information, I would begin with a relational database like SQL, given the structured nature of the data. Each planet would have attributes such as name, distance from the sun, mass, size, and others, which could be organized as columns in a planets table. For querying purposes, I would utilize SQL’s built-in querying features, which support filters, joins, and aggregations. To sort the data, SQL offers the 'ORDER BY' clause for this purpose. Lastly, to address scalability concerns, I would explore sharding the database—dividing it into several smaller databases, each containing a subset of the data. For example, this could involve creating a separate database shard for each Solar System.