Suggestion: Compare scaling solutions (e.g., sidechains)

[Geremia]

A chapter or appendix comparing the various scaling solutions would be good.

Discussing side-chaining, and how it could help with the scaling problem, would be good, too:

Mastering Blockchain, for example, only has this on sidechains:

Sidechains
More precisely known as pegged sidechains, this is a concept whereby coins can be moved from one blockchain to another and moved back. Common uses include the creation of new altcoins (alternative cryptocurrencies) whereby coins are burnt as a proof of adequate stake. There are two types of sidechain. The example provided above for burning coins is applicable to a one-way pegged sidechain. The second type is called a two-way pegged sidechain, which allows the movement of coins from the main chain to the sidechain and back to the main chain when required.

Sidechains (cf. Blockstream / the whitepaper, Elements Project / its GitHub repo, etc.) could be elaborated upon in Mastering Bitcoin's 2^nd ed., perhaps in a section comparing all the various scaling solutions.

[wbnns]

@Geremia Thanks for the suggestion. Leaving this open so that it can be considered as potential new content to include in the future.