Ask HN: Dynamic data in a database

I am trying to figure out whether or not I should make the switch from a standard database to something new and fancy like mongodb, but I am still unsure how my problem fits into either solution.

Essentially what I have is data that grows with time, so a column based database seems likely to cause headaches in the near future. I should also note that I receive all my data in a JSON format, so I was leaning towards a mongo solution given those facts. It seems pretty keen on storing data in that object based format.

I think my only concerns are how do you do match up data from one collection to another. Say for instance I wanted to organize my data in such a form so that I had an entry collection, a hash data collection and then a results collection. How would I associate those details with a given entry within the entry collection? Or would I just store it all together?