S-expression stored in sql database

[foobaring foobaring]

Hello. Can this be a solution to the s-expression storing

The advantage of storing it this way is that the database grows in data, not in structure. The number of possible s-expression is essencialy infinite, and that could make changing the structure (tables and columns) prohibitive in a relational database.

Obs: 

 - Instead of the column "type" in the Nodes table, it could be a boolean column "is_set"
- I use a "equal" relation for asigning two nodes