Overview

• Decentralized data ecosystems

• Issues faced

• Research questions

• Evaluation

• Conclusion

What are decentralized data ecosystems?

Around Consumers

Around Producers

1. Relives SMEs cost
2. Data quality
3. Sparks innovation

Access path dependency halts adoption

De Smet Jitse, et al. "SGF: SPARQL Updates over Decentralized Knowledge Graphs without Access Path Dependencies"

Structural descriptions can help

De Smet Jitse, et al. "SGF: SPARQL Updates over Decentralized Knowledge Graphs without Access Path Dependencies"

Asymmetry is needed but breaks write semantics

Symmetric interfaces

Asymmetric interfaces

Dedecker, Ruben, et al. "What's in a Pod? a knowledge graph interpretation for the Solid ecosystem."

Complexities of interface heterogeneity

Verborgh, Ruben, et al. "Web-Scale Querying through Linked Data Fragments."

Interface heterogeneity tackled for reads

Taelman Ruben et al. "Comunica: A Modular SPARQL Query Engine for the Web"

RQ1: How to balance overall write throughput and server-side performance when updating data across a large network of permissioned, decentralized and heterogeneous RDF data stores?

Datasets exposed as polyglot system

RQ2: What are the requirements for update interfaces in decentralized environments, and how do they differentiate themselves?

Literature review

Khine, P.P., Wang, Z.: "A review of polyglot persistence in the big data world"
Hartig, Olaf: "A formal framework for comparing linked data fragments."

Self descriptive interfaces

RQ3: How can interfaces describe themselves sufficiently such that automated agents can interact with them?

Feedback loop
Hydra, OpenAPI, MCP

Markus Lanthaler. "Hydra Core Vocabulary"

Schedule update over single dataset

RQ 4: How to schedule the execution of an update query over a single data store?

SolidBench

Schedule update over multiple datasets

RQ 5: How can we schedule an update query over multiple data stores?

SolidBench

ACID transaction across datasets

RQ 6: How can we support the atomicity property of ACID-transactions across multiple data stores?

SolidBench & battle test

Evaluation by extending SolidBench[8]:

1. Update execution time
2. Number of HTTP requests
3. Number and scope of transaction locks
4. Recovery time of transaction rewind
5. Inconsistent state durations
6. Robustness against random failures

Ruben Taelman. "Evaluation of Link Traversal Query Execution over Decentralized Environments with Structural Assumptions"