How to save R list object to a database?
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Suppose I have a list of R objects which are themselves lists. Each list has a defined structure: data, model which fits data and some attributes for identifying data. One example would be time series of certain economic indicators in particular countries. So my list object   has the following elements: 

  `data` - the historical time series for economic indicator

  `country` - the name of the country, USA for example

  `name` - the indicator name, GDP for example

  `model` - ARIMA orders found out by `auto.arima` in suitable format, this again may be a list.

This is just an example. As I said suppose I have a number of such objects combined into a list. I would like to save it into some suitable format. The obvious solution is simply to use `save`, but this does not scale very well for large number of objects. For example if I only wanted to inspect a subset of objects, I would need to load all of the objects into memory. 

If my data is a `data.frame`  I could save it to database. If I wanted to work with particular subset of data I would use SELECT and rely on database to deliver the required subset. SQLite served me well in this regard. Is it possible to replicate this for my described list object with some fancy database like MongoDB? Or should I simply think about how to convert my list to several related tables?

My motivation for this is to be able to easily generate various reports on the fitted models. I can write a bunch of functions which produce some report on a given object and then just use `lapply` on my list of objects. Ideally I would like to parallelise this process, but this is a another problem. 
