The traditional approach to efficiently modelling data like that with relational databases is to use the EAV[1] model, which works quite well in practice. [1]:

The traditional approach to efficiently modelling data like that with relational databases is to use the EAV[1] model, which works quite well in practice. [1]: https://en.wikipedia.org/wiki/Entity%E2%80%93attribute%E2%80%93value_model https://en.wikipedia.org/wiki/Entity%E2%80%93attribute%E2%80...