Scalability – "Centralized relational databases" versus "Decentralized block chain": Which is really more scalable?

(Note: My answer is based on the assumption that "Blockchain = Bitcoin Blockchain." This does not apply to file block strings such as SiaCoin or Storj)

It depends on how you define "scalability" and "centralized".


If you mean

centralized = on a large computer

Yes, the blockchain could be more scalable, as it can be fragmented: Here is the huge section of frequently asked questions about the fragmented Ethereum.

centralized = many computers in a large company

Relational databases can also be fragmented, so scalability depends on the type of data.

Type of data

Immutable data / data with version tracking.

Blockchain may or may not be a better option, it depends on the implementation.

Mutable data

It is not a good idea to use an immutable blockchain to keep the data mutable. You can simply push the changes to the block chain. Instead, you will have to scan the blockchain from start to finish if you need to access a file, unless the current files are so small that you can save a copy. (<- Which are larger, the files or the version history of the files? It gives shape to how scalability is defined).