The RR diagrams are images, while the SQLite diagrams are SVG. In my view, SVG is better: it allows copy & paste. SVG would also allow adding links directly in the diagrams, but SQLite doesn't have that (so far).

The diagrams for the H2 database [1], and Apache Jackrabbit Oak [2], do have links. (I wrote the generator for those.)

[1] https://h2database.com/html/grammar.html [2] https://jackrabbit.apache.org/oak/docs/query/grammar-sql2.ht...

One major caveat for the SQLite diagrams in particular - they are written by hand, not from the computer-readable parser description.

This means that there are sometimes blatant bugs and ambiguities. Test your AST assumptions against a real SQLite!