postgresql-12-toastinfo binary package in Ubuntu Focal arm64

 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.

Source package