Using the ledger to host data

DavidBachmann

It is my understanding that I can use the distributed ledger to store data as XDR. This action is free (?) but the more data I store the more Lumens the account needs to have.

If I understand correctly I will need to create a new transaction with operation type of 'Manage Data' and use the XDR library to encode my data (likely a JSON file). This string of data then lives on the ledger and anyone can read from it and decode.

Am I close? I have yet to find example code or even a transaction containing such data that I could observe.

Thanks!

bkolobara

DavidBachmann XDR is just a data exchange protocol, like json. I think the data per account is limited and the Stellar network is not optimised for this use case (storing data on the ledger). Maybe you can work around it, but it's not straight forward.

OrbitLens

DavidBachmann There are some limitation applied to data storage.

Both data key and value are limited to 64 bytes (datavalue column in db is defined as varchar(112), however, @zcc mentioned earlier that data in fact is also limited to 64b, maybe 112 is a max size in base64 encoding).
Each data entry for account requires 10XLM reserve (https://www.stellar.org/developers/guides/concepts/fees.html#minimum-account-balance). So if you want to add, say, 10 entries to some account, the account need to have at least 120XLM on it.

DavidBachmann

bkolobara Thanks for the answer. I will experiment with this some more.

DavidBachmann

OrbitLens Does that mean the reserved lumen are stuck in the account forever? Thanks for the informative answer.

OrbitLens

DavidBachmann Reserved amount remains on the account balance until you remove the data entry.
If you want to reclaim all reserved funds, it can be done using Merge operation (https://www.stellar.org/developers/guides/concepts/list-of-operations.html#account-merge).