This PostgreSQL extension exposes the internal storage structure of variable-length datatypes, called varlena.

The function pg_toastinfo describes the storage form of a datum:

* null for NULLs * ordinary for non-varlena datatypes * short inline varlena for varlena values up to 126 bytes (1 byte header) * long inline varlena, (un)compressed for varlena values up to 1GiB (4 bytes header) * toasted varlena, (un)compressed for varlena values up to 1GiB stored in TOAST tables

The function pg_toastpointer returns a varlena's chunk_id oid in the corresponding TOAST table. It returns NULL on non-varlena input.