Distributed Databases, Distributed Ledger and Blockchain. Which is Which?



Few days ago I witnessed a heated discussion on one of my contacts’ LI page over the differences between distributed databases, distributed ledger and blockchain technology.

The discussion and the differing points of view weren’t, surprisingly, surprising at all! They, merely, reflect the bigger controversy in the field over these technologies, especially DLT and BC.

According to Fortune a Google search for “blockchain” returns 215 million websites, while “distributed ledger technology” returns only 1.3 million.

Some experts and publications tend to use the acronym DLT over blockchain to describe the technology from a wider perspective or to avoid getting into the different classifications of blockchain technology types, which is a thorny issue in its own right.

While businesses tended to use blockchain technology to benefit from the hype surrounding the technology, it seems that this trend is changing with the different levels of maturity attained in the market.

Further, blockchain as a term is more associated with public permissionless blockchains, especially bitcoin, which is not welcome by different governments nor its underlying technology.

Therefore, DLT is emerging as an alternative to be used by high-end firms and mainly financial institutions, which apply the technology in a centralised manner or with a different modus operandi diverging sharply from the main characteristics of a public permissionless blockchain.

Anyway. While I was conducting my habitual and ritual daily research routine on BC technology, I stumbled again upon an old study – though it was conducted in 2017 – which I read many months ago. It discusses BC technology, its emergence and ecosystem. It has many interesting information which may fill the gaps in knowledge for many non-techies like myself.

I have found a small section which addresses the differences between the three technologies, DD, DLT and BC. I, gladly, present what I have read with minimum to no editing.

Below is a framework that can be used to distinguish between traditional distributed databases, distributed ledgers, and blockchains. Distributed ledgers are a subset of distributed databases, and blockchains are a subset of distributed ledgers.





The comparison list  below is not exhaustive. It is just and attempt to show the main differences between each type.

What is described below is mainly about public blockchains.



*Image and table reproduced from Global Blockchain Benchmarking Study by Dr Garrick Hileman & Michel Rauchs 2017