Databricks Genie Ontology Needs Clean Data First

Databricks Genie Ontology works on day one, but Databricks says the best answers still depend on the data underneath.

The Sept. 1 guide from Srujan Alase, a Databricks engineer, and Richard Tomlinson frames the setup as six layers. They call it a maturity path, not a list of prerequisites.

Think permissions-first AI. Agents only see what Unity Catalog allows, and they rank context by authority and relevance before answering.

How the approach works inside Databricks Genie Ontology

Large language models can reason, but they don't know your business definitions. Without help, they guess at joins, metrics, and terms.

Databricks splits the fix into a modeled head and an inferred tail. You deliberately define critical semantics. Genie learns the rest from governed tables, queries, dashboards, and notebooks you already use.

Layer 0 is the physical foundation. Clean gold tables. Clear grain on facts. Conformed dimensions and one golden record per entity, so a customer isn't three different IDs.

Layer 1 adds descriptions and column comments in Unity Catalog, plus governed tags for PII, PHI, and ownership. The dbxmetagen accelerator can draft them. Humans still have to approve.

Layer 2 builds the logical model. Declare primary and foreign keys so agents don't invent joins, then define measures and dimensions once in Metric Views.

Think of Metric Views as the official recipe. The aggregation is resolved at query time, so everyone uses the same governed definition for revenue or active customers.

Why this matters, and what still goes wrong

For builders, this is where AI agents break in production. A wide table with mixed grains and duplicated metrics will get answered confidently and wrong.

The mitigations are concrete. Use Metric Views with display names, synonyms, and example queries. Group assets in Domains and document terms in Pages that point to authoritative sources.

Genie Code helps too, including /importBI to bring in Tableau or Power BI models as Metric Views, and bulk import for Pages. External agents can also call the same intelligence via MCP.

What isn't fixed is enforcement. Relationships in Unity Catalog are informational, not enforced, so governance has to keep them accurate. Layer 3 through Layer 5, curate trusted assets, govern access, and continuously evaluate, is where drift returns if you stop.

Start with one domain. Every resolved entity and certified metric improves the next answer.