In an app, I'll be storing information about
session_id url time type data: foo: bar bar: foo
The data will basically be a hashmap (need to support arbitrary types / names of variables)
And I need to be able to perform a query like,
select events of type pageview in which a user (known by session_id) visited url "some url", then visited a page "page 2 url" (again taken from another event of type pageview), and had data.foo = bar in step 1, and data.foo = foo in step 2.
select median of visit duration of all unique sessions, where visit duration is (last visit time - first visit time) <= 6 hours
Q: I would have to use a schemaless database, as storing each data element in a different record would require potentially dozens of joins, right?
Q: What database would you use for this?