A database term describing the breaking up of a single database into smaller, more manageable pieces so that its’ data can be accessed more efficiently. The eth2 sharding project (Phase 1) has borrowed this tactic by breaking up “storage and computation of the whole system into shards, processing the shards separately, and combining the results as needed. Specifically, eth2 implements many shard chains, where each shard has similar capabilities to the eth1 chain. This results in massive scaling improvements.” (R2)
Blockchains are essentially databases holding historical data with each new entry adding to the security of the whole, because each new entry adds to the integrity of the decentralized trusted ledger. Sharding a database is a scalability tactic being used in eth2 because it allows the total amount of data to exceed the capacity of any individual eth2 blockchain shard. Per
the sharding Github FAQ: “We want to be able to process 10,000+ transactions per second without either forcing every node to be a supercomputer or forcing every node to store a terabyte of state data, and this requires a comprehensive solution where the workloads of state storage, transaction processing and even transaction downloading and re-broadcasting are all spread out across nodes.” (R1)
The eth2 blockchain will be divided into separate shards (aka “buckets”). PoS nodes will only have to run the part of the ledger they are assigned to validate transactions, instead of maintaining the whole ledger. In its’ attempt to balance the blockchain trilemma (security, scale, and decentralization) BFT PoS validation is looking to evolve the original decentralized Internet that birthed Bitcoin PoW to challenge the scale of existing payment systems: “while most Byzantine Fault Tolerant Proof of Stake protocols scale to tens (and in extreme cases, hundreds of validators), eth2 is capable of having hundreds of thousands of validators all contributing to security without compromising on latency or throughput” (R2)
REFERENCES:
R1: https://eth.wiki/sharding/Sharding-FAQs
R2: https://blog.ethereum.org/2020/03/27/sharding-consensus/
R3: https://cointelegraph.com/explained/sharding-explained
R4: https://medium.com/chainsafe-systems/ethereum-2-0-a-complete-guide-scaling-ethereum-part-two-sharding-902370ac3be
R5: https://docs.google.com/presentation/d/1G5UZdEL71XAkU5B2v-TC3lmGaRIu2P6QSeF8m3wg6MU/edit#slide=id.p4 (header diagram by Hsiao-Wei Wang )