When blockchain networks utilizing proof-of-work create blocks simultaneously, only one is chosen for addition to the chain. Known as an ommer block in Ethereum, other blockchains refer to such blocks as uncle or orphan blocks, linking them to familial roles describing their relative positions.
With Ethereum’s switch to proof-of-stake from 2022, which rendered the creation of ommer blocks a non-issue, other proof-of-work blockchains continue to generate these additional blocks.
In Ethereum and Bitcoin’s public blockchains, employing a method to verify and add data through consensus is vital. Keeping data unchanged is of equal importance, handled by several blockchains using Merkle trees.
Merkle trees form genealogical connections for data blocks, where new blocks carry forward previous blocks’ data, akin to DNA inheritance. This conceptualizes the terms parent, parent’s sibling, child, and sibling blocks, reminiscent of a family tree diagram.
The Ancestral Analogy
Block A serves as the root, with subsequent blocks building upon it; the first offspring, block Ba, contains not only its data but also that of its predecessor, A.
Known as block B or Ba, this progeny block exemplifies the ongoing chain of data inheritance, shaping an intricate family tree and blockchain. The naming convention links B to its lineage.
From Ba, simultaneous validation of two blocks results in Cab and Cab2, siblings diverging from a common parent. Cab gains entry to the blockchain, leaving Cab2 as an unvalidated offshoot. Another extension from Cab, marked as Dcab, highlights Cab2 as an ommer block, derived from Dcab’s ancestor.
These blocks emerged as unintended coding outcomes, a phenomenon Ethereum capitalized on by motivating ommer block miners through:
- Paving the way to generate more ommer blocks from reduced block times, boosting network velocity.
- Discouraging incentive centralization within dominant mining pools that spared limited rewards for small-scale miners.
- Enhancing blockchain security by acknowledging work done on ommer blocks alongside the main chain.
Ethereum Classic, diverging from the Ethereum core post-2016 DAO breach, persistently yields ommer blocks, albeit branded as uncle blocks.
The traditional designation of an ommer block stemmed from the term “uncle,” but it was reevaluated by Ethereum’s community, opting for more inclusive terminology. Ethereum’s proof-of-stake shift renders ommer blocks obsolete.
The ommer rate, historically termed the uncle rate, quantified ommer block production relative to transaction volume. The Ethereum main chain no longer maintains such a rate due to the transition.
Ommer block rewards, consisting of a partial block reward and transaction fees, tied into the previous consensus model. The 2022 shift to proof-of-stake eliminated ommer block creation.
Reflecting on Mining Incentives and Ommer Block Relevance
The proof-of-work era of Ethereum witnessed unaccepted ommer blocks incentivized alongside accepted ones due to their creation efforts. Post-2022’s “The Merge,” Ethereum’s proof-of-stake model marked the end of such blocks.
Analyses, opinions, and insights provided here serve purely informative intentions. Further details are available on the relevant online resources.