even those with some public history, should be considered to be fungible with
other sats with no such history.

=== Backward compatibility ===

Ordinal numbers are fully backwards compatible and require no changes to the
bitcoin network.

=== Drawbacks ===

==== Large Index Size ====

Indexes supporting fast queries related to ordinals are slow to build and
consume large amounts of space.

An O(1) index that maps UTXOs to the ordinals that they contain is currently
100 GiB. The same index including spent outputs is 10 TiB.

An O(1) index supporting the opposite mapping, that of individual ordinals to
the UTXO that contains them, is likely to be intractable. However, an O(n)
index where n is the number of times an ordinal has changed hands, is fast and
practical.

==== Large Location Proofs ====

A proof can be constructed that demonstrates that a particular sat is contained
in a particular output, however the proofs are large. Such a proof consists of:

- Block headers
- A Merkle path to the coinbase transaction that created the sat