Rescan in pruned mode

[chris-belcher]

Electrum Personal Server works with Core's pruned mode, but that disables rescans. That means people who have a pruned full node and a wallet with historical transactions cannot easily adopt EPS.

I actually managed it in 2016 on JoinMarket which works the same way as EPS: JoinMarket-Org/joinmarket#431 (comment)

It is totally possible to have Core download blocks needed for rescanning while still keeping pruned enabled. One of these days I'll try to put some time into figuring out exactly how and writing a guide on it.

[MrPaz]

Just popping in to say this feature would be great. I use EPS on both a full node at home and pruned node on a work laptop, and often it's been a slight pain point not being able to use particular wallets on the work laptop.

[chris-belcher]

@MrPaz if you have an unpruned node you could rescan the wallet on it, and then copy over the wallet.dat file to your pruned node.

[MrPaz]

Oh really? So if I rescan the electrum wallet file on full node computer then put it on the pruned node computer it will have full history? That's nice.

What actually happens during rescan? ie What data is saved in the wallet file? Blocks with relevant transactions?

[chris-belcher]

Oh really? So if I rescan the electrum wallet file on full node computer then put it on the pruned node computer it will have full history? That's nice.

Yep it should do.

What actually happens during rescan?

Transactions and metadata (e.g. block hash which contains that tx) are saved in the wallet.dat file.