Partial Catch-up on Validator nodes

Question

I'm curious to know what would happen in the following scenario:

Suppose I have a network of 7 validator cores of which 4 performed a complete catchup (replay) of history (say a month's worth of ledgers) and 3 performed a limited catchup - say 1 day's worth of ledger.

What would happen if:

1. I request the account info of an account that's OLDER than than a day, from a horizon connected to a core with partial history? Would I get 404?

2. Suppose a transaction is requested for such an account. How would the partial cores be able to verify it? Would this tx even succeed?

Answer 1

Having consulted my local expert, it appears that when I perform a partial catchup, the core retrieves the entire state of the blockchain, just not the entire transaction history of the blockchain.

So:

1. the core would still know every account in the blockchain
2. the core would also be able to verify txs related to every account
3. the core would just NOT be able to provide the tx history of accounts that it had not replayed.

In other words, the only incentive to perform full catchup is this: if you need to provide the full transaction history (for example to a horizon that supports an explorer-type UI), then you need to perform full catchup.

Regardless of whether you chose to perform full or partial catchup, your core will be able to provide the balance of any account and verify new transactions for any account.