How can Mithril update the transactions after taking the snapshot?

Question

Question: When I check the Mithril explorer, The snapshots will be saved in Mithril Aggreagtor 5 times a day. Light wallets can then download this snapshot to see their transaction history without downloading the full node. But snapshots only provide pre-snapshot transaction information. If after the snapshot is created, I make a transaction, will the transaction be updated on my wallet? Or do I have to wait 4 hours for the next snapshot of my transaction to be updated?

Answer: It would depend on the specifics of your wallet, but the idea is that a (heavyweight at least) wallet would start with a snapshot taken at some point in the past, and then "follow the chain" from that point on, a process that should be pretty fast (eg. seconds or minutes) to reach the tip of the chain.

Once there, it will proceed as normal and your transaction will certainly be reflected in your wallet's state and on-chain as soon as possible, eg. pending confirmation.

=> Question: So what is the mechanism of heavyweight wallet? How can it follow the chain?

Answer 1

A heavyweight wallet can follow the chain by running a node. When starting a node from scratch, it takes probably a few days to have it in sync. Mithril reduces this to minutes (or tens of minutes). A wallet cannot see transactions history in the Mithril archive. A node is required for that, and actually not only a node, but also a chain index like cardano-db-sync or something similar. Not all information required to be displayed in a wallet can be extracted directly from the node, that's why a chain indexer is required. I hope this answers your question.