A potential "quick" solution could be to identify the most frequent fields, create a postgres table with those as columns (with relevant indexes) and then add t

A potential "quick" solution could be to identify the most frequent fields, create a postgres table with those as columns (with relevant indexes) and then add the rest to a JSONB fields. This would allow you quick lookup on specific columns, while still giving you access to the rest of your data as part of SQL queries (postgres 9.5+ has a lot of nice JSON operators as well as indexing options). Besides that, a column store might be what you are looking for if you are more interested in aggregate data on specific columns?