Querying in Solid

Ruben Taelman

SIB RDF focus group, 12 March 2024

Querying in Solid

Ghent University – imec – IDLab, Belgium

The Web is in control of tech giants



Image credit

Solid aims to re-decentralize the Web

A Web-based decentralization ecosystem

Solid Logo

Solid is a collection of open standards

Solid is an ecosystem

Personal data pods

Full control of where your pod is stored and who can access it

Solid Pods

Pods can store any kind of data

Personal data, photo's, friends, ...

Solid Pods Storage

Data become decoupled from apps

Centralized App      Solid App

A paradigm shift in app design

Users gain freedom to choose apps

SPARQL processing over centralized data

How to query over decentralized data?

Federated SPARQL querying?

Link Traversal Query Processing!

LTQP was designed for querying Linked Open Data

Exploiting structural properties of Solid

Non-complex queries can be answered in the order of seconds


Taelman, R. Link traversal query processing over decentralized environments with structural assumptions. ISWC 2023.

Inefficient query plans

Hybrid query execution

Query API in a Solid pod

Exploit structural information

Structure in a Solid pod

Reasoning at query time

Summarization across multiple pods

Summary over Solid pods

Solid aims to redecentralise the Web