I've recently started developing an extension for Postgres for which I'll need to create a new variable-length base type. The type will require a tree-like structure in order to parse sufficiently, which of course probably means having some sort of recursive data structure, like a struct that has members which are pointers to itself for child nodes. After doing some research, specifically looking at how other variable-length data types store their data, it seems almost all of them store the data in a binary representation, using bit masks and offsets etc in order to store/access the data whilst having an in-memory representation that's used to manipulate the data.
I presume the purpose for using this approach is because all the data in a varlena type has to be contiguous, and the moment you start using pointers this is no longer possible. So my question is, given a structure that looks something like this,
typedef struct Node
{
char *data;
Node *left;
Node *right;
} Node;
am I right in saying that I wouldn't be able to store that representation on-disk, but instead I'd have to transform it into some binary representation and back again when writing/reading respectively, are there any alternatives?
