Dmitry Dolgov <9erthalion6(at)gmail(dot)com> writes:
> * is that a good idea to extend the `ArrayRef` for jsonb?
No. Make a new expression node type.
(Salesforce did something similar for an internal feature, and it was a
disaster both for code modularity and performance. We had to change it to
a separate node type, which I just got finished doing. Don't go down that
path. While you're at it, I'd advise that fetch and assignment be two
different node types rather than copying ArrayRef's bad precedent of using
only one.)
regards, tom lane