Current permissioned blockchain systems utilize the keyvalue data model to store and query the ledger. As the key-value pairs are not su ciently expressive to represent relationships between data, we present a proposal for the utilization of triples as the data model for blockchain systems. This approach enables a powerful query engine and reduces the number of data stores that have to be maintained.
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Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0). 2 World State
Key-value store (Document store)
is derived from r ge 1 Blockchain d e L
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... lep key value xamCAR0 {color:“blue“,make:“Ford“} E latest application state queries
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Engine queries historical application state queries latest application
state latest application state lxaEepmeCCnAAtRRit00y ccaaatrtr/r/imcboualokteer vFbaolluruede Me<rkTl.rei.p.Ble->tree directly on the blockchain data, eliminating the maintenance of additional data stores. Our approach addresses the key issues of preserving the integrity of the blockchain's data structure, maintaining an e cient data representation, and supporting a powerful query engine.
Our blockchain ( 3 in Figure 1) implementation utilizes Merkle B-trees [
This implementation, however, has high storage requirements and requires several optimization mechanisms. The use of techniques such as data compression, data deduplication, and data encoding as well as the reuse of already stored data structures contribute to reducing storage usage.
Future work will entail the research of further optimization mechanisms, the mechanism and format for exposing the triple data model to smart contracts as well as the development and evaluation of a prototype implementation.