Advanced querying


On this page

    The following guides explore some of the more advanced concepts when querying using Comunica.

    HTTP Basic Authentication

    Send authenticated HTTP requests by including username and password.

    Caching

    When remote sources are requested, caching allows them to be reused in the future.

    Passing a context

    A context can be passed to a query engine to tweak its runtime settings.

    Destination types

    Comunica detects and handles different types of destinations.

    Extension Functions

    Providing implementations for SPARQL extension functions.

    Federated Querying

    Query over the union of data within any number of sources

    GraphQL-LD

    Using the power of JSON-LD contexts, GraphQL queries can be executed by Comunica

    HDT

    HDT offers highly compressed immutable RDF storage.

    Logging

    Loggers can be set to different logging levels to inspect what Comunica is doing behind the scenes.

    Memento

    Using the Memento protocol, time travel queries can be executed.

    HTTP Proxy

    All HTTP requests can optionally go through a proxy.

    RDF/JS

    To achieve maximum interoperability between different JavaScript libraries, Comunica builds on top of the RDF/JS specifications.

    Querying over RDF/JS sources

    If the built-in source types are not sufficient, you can pass a custom JavaScript object implementing a specific interface.

    Updating RDF/JS stores

    If the built-in destination types are not sufficient, you can pass a custom JavaScript object implementing a specific interface.

    Result formats

    Query results can be serialized in different formats.

    Solid

    Solid – the Web-based decentralization ecosystem – can be queried with Comunica.

    Source types

    Comunica detects and handles different types of sources.

    SPARQL query types

    Different SPARQL query types are possible, such as SELECT, CONSTRUCT, ASK, ...

    Supported specifications

    Comunica supports several RDF-related specifications