Grakn utils: schema development toolkit

utility toolkit for developing a grakn schema.

Why

Existing ontology languages like OWL have dedicated tools such as Protege that reduce the pain of building an ontology by letting the developer

• include metadata such as definitions, elucidations, examples, references, revision history
• visualise the ontology as a graph
• export the ontology to different formats

With Grakn there are two ways to develop a schema: writing a series of 'define' statements in a gql file or using the WorkBase GUI. Both fall short of the above requirements.

How

This toolkit uses Grakn as an environment for developing a Grakn schema.

Specifically, the developer encodes the new schema classes as instances of classes of a 'meta-schema' through a script of graql insert statements.

The developer visualises the ontology using the WorkBase data visualiser, enabling far more flexible queries and click-based interaction than the built-in schema visualiser.

When the developer has written the schema in 'insert' form, the parser script compiles it to a series of define statements - the standard grakn schema format.

Example

Inspect the schema_meta.gql file to understand how it models classes and their relations (e.g. class inheritance). .gql contains a simple schema in 'insert' data form. Use this as a template. To compile the schema into a set of 'define' statements do <run compile script>

Questions and answers

• Why not just add schema metadata as attributes within the schema?
  • It would be inappropriate for each data instance to include attributes with metadata about its ontology class as instances will already have attributes with instance metadata.