January 2019
Beginner to intermediate
372 pages
11h 17m
English
Though the blockchain doesn't allow data to be modified, previously stored data can be updated by creating a new transaction. It's important to note that transactions are not processed quickly in blockchain networks, and it's recommended to wait for a certain number of block confirmations even after the transaction is included in the block. If a particular data item needs to be updated very often, it will take a considerable amount of time before all the interrelated transactions are processed. Many nodes might even reject such transactions that reference other unconfirmed transactions. So, it's recommended to store and process such data off-chain.