JSON Fields (problem set dates in particular)

[drdrew42]

We must be very deliberate with what we put in JSON fields in the DB as it becomes much more expensive to filter/sort on their contents.

With the problem set dates, we have a situation where some sets will have dates, others will not. And even those that have dates might have different combinations of 2 to 3 relevant dates. Because of these inconsistencies, we either need:

• different tables for each type of set (difficult to expand the variety of supported problem set types -- do we think this will happen?)
• one table for all types, with multiple null-able date fields
• the JSON approach where differences between sets are masked behind the JSON field type

Relevant considerations:

• how often will we need to filter/sort by date?
• what is the marginal cost of using the frontend to filter/sort as opposed to requesting the DB to filter/sort?

Let's plan to discuss the pros/cons of these options relatively soon -- as we will likely be developing features that rely on these dates in the very near future.