Something that I've used in the past: store the hierarchical data as a breadcrumb-like string in an ordinary column. This means the parsing is just ordinary csv

Something that I've used in the past: store the hierarchical data as a breadcrumb-like string in an ordinary column. This means the parsing is just ordinary csv parsing, followed by a relatively trivial extra step to parse the breadcrumb columns. You also retain the ability to describe arbitrary depth hierarchies: country,value World/Asia/China, 1409517397 World/Asia/India, 1339180127 World/Asia/Indonesia, 263991379 An added benefit of this approach is that you can have hierarchies in multiple columns. For example: datetime, source_account, destination_account, amount 2016-07-01, Assets/ProjectFunding, Assets/Capital/Delivery, 134.2 2017-07-01, Assets/ProjectFunding, Assets/Capital/Delivery, 72.2 2016-07-01, Assets/ProjectFunding, Assets/Capital/Other, 5.0 2016-07-01, Assets/ProjectFunding, Expenses/Development, 4.7 2017-07-01, Assets/ProjectFunding, Expenses/Development, 1.6 2017-07-01, Assets/Cash, Expenses/OPEX, 0.96 2018-07-01, Assets/Cash, Expenses/OPEX, 1.62