[lincpa]

If Clojure is the sea, programming is to sail on the sea, I use the relational model as a lighthouse and route, as a reference model for simple programming, because the relationship theory is simple and scientific..

I had implemented a DataFrame with hash-map, which implements relational operations. A relational operation is just a function. The advantage of hash-map is that key-chain can be used as a pointer, and processing data elements is simple and efficient. Therefore, DataFrame has advantages of RMDB and NoSQL.

A strict relational model will lose the flexibility of data element operations.