Hi All,
I talked with Pieter off-list. And I guess the main opposition is that coins that are coming from chains that you are not directly validating are not fully validated by you in the sense that you only get an SPV type proof to prove that miners have accepted those coins. Yes, it's true, but once blocks have been mined, there is nothing you can really do about it. Splitting up the transactions into multiple chains doesn't stop someone from validating all chains, which results in the same validation workload as a full node with one chain and big blocks that store the same number of transactions per second. So there is no disadvantage from using this method compared with having big blocks, and there are clear advantages. The only excuse is laziness to create a proper system.
Martin: I'm not sure if random independent chains would be so useful since there are delays with cross chain transfers and you would not be sure if those chains will be maintained in the future. My idea is more the idea of extension blocks, i.e. synchronised chains.
Also, some people think that CPU speed and memory size are the only limitations to running a full node, and they think that it is ok to just run a heavily pruned node. Pruned nodes (nodes that have less than 10 years of transactions on their hard drives) are bad for the network. Reasons why you would want the long term history of transactions on your hard drive:
1) Your computer could have been compromised when you did the
initial validation, so you may want to validate and see all the old
transactions again.
2) You don't have to spend much time to
download transactions that you want to analyze but have already pruned.
3) Risk of denial of service attack from the
"archival" nodes.
4) There is less of an inequality
between the big data centers and regular people. We can analyze the
history of the transactions that are relevant to us just as effectively
as the data centers. With the pruning model, it will be more like
NSA-style nodes watching our transaction history, while regular people
can only see "snapshots". Remember how the Bitcoin community was analysing the old Mt Gox transactions using the blockchain? This kind of stuff will no longer be possible if most people can only run pruned nodes.
5) The data is more
distributed thus more easy for others to download (think torrent
downloads vs downloading from a central server).
6)
Again being distributed, more eyes will be looking at the long term
data, thus people can more easily investigate scandals and things like
that.
7) Without the full history of blocks people
cannot really give a proof to others that what they noticed with their
pruned nodes is actually what happened (if they spot something
interesting).
8) The time for a new user to start fresh and sync a full node with a long term history of transactions is much more accessible (17 days for 100 years of transactions with 1 MB blocks on high-end computers). Same with the time needed to perform any kind of analysis on the old transactions. And remember, any new transactions likely depend on old transactions, so yes they are very relevant.