pg_liquid

pg_liquid brings Liquid-style graph, compound, and ontology querying into PostgreSQL as a native extension.

It is built for teams that want to:

• store graph facts as ordinary PostgreSQL data
• express ontology and workflow relationships with Liquid syntax
• query recursive graphs without standing up a separate graph database
• enforce principal-scoped reads with extension-level policy rules

What You Can Do

• Create graph facts with Edge(...)
• Define structured compound types such as Email@(...) or OntologyClaim@(...)
• Write recursive query-local rules
• Build ontology vocabularies directly in graph data
• Project relational tables into Liquid compounds with row normalizers
• Expose least-privilege reads through liquid.read_as(...)

Start Here

1. Install pg_liquid
2. Create your first graph
3. Query a graph
4. Build an ontology

Compatibility

pg_liquid is currently validated against PostgreSQL 14, 15, 16, 17, and 18.

Core SQL Surface

liquid.query(program text)
liquid.query_as(principal text, program text)
liquid.read_as(principal text, program text)
liquid.create_row_normalizer(source_table regclass, normalizer_name text, compound_type text, role_columns jsonb, backfill boolean default true)
liquid.drop_row_normalizer(source_table regclass, normalizer_name text, purge boolean default true)
liquid.rebuild_row_normalizer(source_table regclass, normalizer_name text)

Learn by Task

• I want to model simple graph edges
• I want to query paths and recursive reachability
• I want typed records and role-based modeling
• I want a real ontology vocabulary
• I want PostgreSQL tables to feed Liquid compounds
• I want principal-aware reads

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