Databricks has made a single coherent bet: the lakehouse becomes the agentic control plane. Every major announcement in 2026 — Genie Ontology, Agent Bricks, Lakebase, Unity Catalog semantic stack, Omnigent — is a layer in one architecture.
Databricks launched the Certified Context Engineer Associate (May 2026) — billed as the industry's first certification for reliable AI agent systems. The cert syllabus defines five layers:
| Layer | What it covers | Databricks Component |
|---|---|---|
| Instructions | System prompts, agent behaviour constraints | Agent Bricks / Genie Spaces |
| Retrieval | Surfacing relevant knowledge at query time | AI Search (formerly Vector Search) |
| Memory | Persisting state across sessions | Lakebase Agent Memory (MemCurrent) |
| Tools | Connecting agents to data and external systems | MCP Catalog + Unity Catalog |
| Governance | Metadata, PII, access policies, quality | Unity Catalog (metrics, glossary, domains) |
These five layers are the SI discovery framework for any agentic engagement. Cert price ~$200. Beta takers report it demanding — not a typical vendor cert.
A live, self-improving knowledge graph of business meaning that grounds Genie agents. Prevents agents from generating syntactically valid SQL that returns the wrong business result.
EXTRACT → Ranked snippets from: UC Metrics (highest authority),
dashboards, SQL history, 50+ app connectors
RANK → OntoRank: creator authority × usage breadth
× dataset linkage × recency
RETRIEVE → At query time: fetch top-ranked snippets,
apply UC permission gate, inject into context window
Benchmark (self-reported): 84.5% first-attempt accuracy vs 52.4% for strongest general-purpose agent. Not independently verified — treat as directional.
| Feature | Status | Notes |
|---|---|---|
| Certified Metrics (Metric Views) | GA | GA Apr 2026; open-sourced into UC OSS v0.5 |
| Domains | GA | GA Oct 8, 2026 |
| Business Glossary | Preview | AI-assisted drafting and drift detection |
| Governance Hub | Private Preview | Single command centre for stewards and admins |
| MCP support (UC functions, Genie, SQL) | GA | OAuth on-behalf-of user |
Two memory layers: Episodic (raw session event log) and Distilled (async background consolidation). Three access patterns: automatic plugins, on-demand tools, background dreaming. All stored in the customer's own Lakebase — data never leaves their cloud.
Unity AI Gateway GA Aug 4 2026 — central control plane for all model access: smart routing, fallback chains, budget hard caps with attribution per user/team/tool, unified tracing into UC system tables, guardrails (PII, prompt injection) in beta.
Omnigent Apache 2.0 · Jun 2026 — meta-harness above existing agent CLIs (Claude Code, Codex, Pi). Declarative YAML: harness is a one-line swap. Policy engine: allow / ask / deny, enforced outside the prompt. Session sharing by URL.
MCP Catalog in Marketplace — governed discovery of MCP tools with credentials managed by Unity Catalog, not in agent code.
| Partner | Accelerator | What it does |
|---|---|---|
| zeb | Agentic MDM for FSI | Reconciles fragmented entities (funds, counterparties, clients) for Basel III / Dodd-Frank / GDPR |
| EY | Data Fusion | Cloud-native AI data management; 2026 FS Partner of the Year |
| Neudesic | Payment Intelligence | Unified real-time payment operations + analytics on Lakebase |
| Genpact | Finance One | Fragmented FP&A data; NL queries; claims 5%+ EBITDA lift |
| Celebal | Agent Garage | Loan origination 30 days → 4 hours (self-reported) |
| Dimension | Databricks | Snowflake | Azure Fabric |
|---|---|---|---|
| Context layer | Genie Ontology (preview) | Cortex Analyst (GA) | Copilot Studio (GA) |
| Semantic / metric layer | UC Metrics (GA, open-source) | Semantic Views (preview) | Power BI semantic model |
| Agent memory | Lakebase MemCurrent (beta) | None native | Cosmos DB (external) |
| Multi-agent orchestration | Omnigent (alpha, OSS) | None native | Semantic Kernel |
| Context engineer cert | Yes — Associate (May 2026) | No | No |
| Theme | Where SI value lands | Maturity |
|---|---|---|
| Context engineering practice | Build the 5-layer architecture for customer agents | New — cert just launched |
| UC semantic stack build-out | Populate Metrics, Glossary, Domains from BI assets | High demand, under-served · 4–8 weeks |
| Agent Bricks implementation | Build + test + deploy governed production agents | Growing — mostly PoC-grade today |
| Lakebase memory architecture | Design persistent agent memory schemas and MemCurrent patterns | Emerging — early-mover advantage |
| Vertical accelerator on Agent Bricks | Build BFSI agent accelerators for Databricks Marketplace | Highest value if Marketplace-published |
| Name | Type | Status | What it is |
|---|---|---|---|
| Genie Ontology | Core product | Preview | AI-facing context layer: modeled + inferred knowledge graph feeding Genie |
| UC Metric Views | Core product | GA | Governed semantic definitions — highest-authority input to Genie Ontology |
| Ontos | Labs | v1.0.0 | Business catalog: data products, data contracts, data mesh on top of UC |
| OntoBricks | Labs | v0.9.0 | Formal OWL ontology → knowledge graph on Databricks, exposed via MCP |
┌─────────────────────────────────────────────────────────┐ │ GENIE ONTOLOGY │ │ │ │ ┌─────────────────────┐ ┌──────────────────────────┐ │ │ │ MODELED CONTEXT │ │ INFERRED CONTEXT │ │ │ │ (you define & certify)│ │ (Genie extracts & ranks) │ │ │ │ │ │ │ │ │ │ · UC Metric Views │ │ · Dashboards │ │ │ │ · Domains │ │ · SQL query history │ │ │ │ · Genie Agent Pages │ │ · Genie Agents │ │ │ └────────┬────────────┘ └─────────────┬────────────┘ │ │ └──────────────┬───────────────┘ │ │ ▼ │ │ OntoRank │ │ (authority × usage × linkage × recency) │ │ ↓ │ │ Permission gate (UC policies) │ │ ↓ │ │ Snippets injected into context window │ └─────────────────────────────────────────────────────────┘
| Signal | What it measures |
|---|---|
| Creator authority | Steward vs. power user vs. anonymous query |
| Usage breadth | How many people and queries rely on this definition |
| Dataset linkage | How closely tied to certified, widely-used UC assets |
| Recency | Freshness of the definition |
YAML-based semantic layer inside Unity Catalog. Define once, query from SQL, BI tools, REST APIs, agents. Advanced features include multi-fact relationships, LOD calculations, parameterised metrics, window measures, measure-on-measure composition.
metric_view:
name: order_metrics
source: catalog.schema.orders
measures:
- name: total_revenue
synonyms: ["revenue", "sales", "GMV"]
aggregate: SUM(order_value)
filter: WHERE status != 'RETURNED'
- name: avg_order_value
aggregate: total_revenue / order_count # measure-on-measure
dimensions:
- name: region
- name: channel
materialization:
enabled: true
refresh_schedule: "0 6 * * *"
dimensions. Known inconsistency — worth flagging in implementations.
| Date | Event |
|---|---|
| Sept 2025 | Snowflake launches OSI with Salesforce, dbt Labs, BlackRock |
| Jan 2026 | Databricks joins; OSI v1.0 spec published under Apache 2.0 |
| Jul 10, 2026 | Donated to Apache Software Foundation; renamed Apache Ossie |
| Aug 2026 | Snowflake ships native SYSTEM$CREATE/READ_OSSIE_YAML (GA) |
| Oct 2026 | PR #152 open — Databricks UC Metric View bidirectional converter |
Databricks joined four months after Snowflake originated it — a defensive move to ensure UC Metric Views' features (window functions, materialization) are represented in custom_extensions rather than lost. No native UI for OSI import/export yet on Databricks.
A Databricks App that adds data mesh semantics UC doesn't natively provide: data products, data contracts (ODCS v3.1.0), domain ownership. React + FastAPI + OWL TTL entity model stored in Lakebase (Postgres).
LLM-assisted OWL 2 ontology generation from UC table metadata → R2RML mappings → RDF triples in Lakebase / Delta / Neo4j → GraphQL API + MCP server for agents.
| Genie Ontology | OntoBricks | |
|---|---|---|
| Approach | Bottom-up (learned from usage) | Top-down (formally modeled OWL) |
| Representation | Ranked snippets (internal) | Standard RDF/OWL triples |
| Reasoning | Not documented | OWL 2 RL, SWRL, SHACL |
| Auditability | Limited | Full (inspectable RDF graph) |
| Target | General enterprise agents | Regulated industries needing auditable knowledge models |
They don't compete — they're designed to layer. Design intent: define the 20% of concepts that cannot be wrong as Metric Views. Let Genie Ontology handle the long tail (80% of business terms that would never justify a formal YAML definition).
Ontos is the preview of what UC Business Semantics will look like in 12–18 months. Customers who need data contracts now use Ontos; those who can wait should watch Governance Hub GA.
DEFINITION TIME
1. Data engineer writes UC Metric View for "revenue" (YAML, versioned)
2. Domain steward adds Business Glossary definition → linked to Metric View
3. Genie Ontology extracts: certified Metric View + dashboard tiles + SQL history
→ OntoRank scores certified Metric View highest
QUERY TIME
4. User asks Genie: "What was our revenue last quarter?"
5. Genie Ontology retrieves top-ranked snippets → UC permission gate
6. Snippets injected into context window
7. Agent generates SQL using certified definition + UC lineage
8. Result returned with source attribution
Without UC Metric Views, step 7 relies on inferred snippets — which can drift or conflict over time.
Databricks' entry into cybersecurity. Agentic SIEM powered by Claude (Anthropic), built on Unity Catalog + Panther (detection-as-code). Runs entirely on the lakehouse — security data lives where business data already lives.
Uses: Lakeflow ingest (OCSF-aligned) → Delta Lake → UC governance (NIS2/DORA) → Agent Bricks agents for detection, triage, threat hunting → Unity AI Gateway traces as security signals.
Three access patterns: Plugins (automatic log/load without agent action), Tools (on-demand explicit query), Dreaming (async consolidation from episodic to distilled). Storage on Lakebase (Postgres) in customer's cloud account — never shared with Databricks.
Sits between all consumers (users, apps, agents) and all LLM endpoints (internal + external). Four capability clusters:
| Capability | What it does | Status |
|---|---|---|
| Access Control | UC-governed per user, team, agent, app, use case | GA |
| Smart Routing + Fallback | Pick model by cost + quality; failover chains; cross-provider | GA |
| Budget Caps | Hard spend stops at token level; attribution per user/team/tool; external provider tracking (Oct 2026) | GA |
| Unified Tracing | Every model call, MCP invocation, agent step → UC system tables → Lakewatch | GA |
| Guardrails (PII, prompt injection, MCP payload logging) | Policy-based rules per use case or MCP server type | Beta |
┌─────────────────────────────────────────────┐ │ AGENT RUNTIME │ │ Manages hosting, identity, scaling on Apps │ │ ↓ │ │ DurableAgentServer │ │ Wraps any framework (LangGraph, CrewAI, │ │ Claude Code SDK, vanilla Python) │ │ API modes: sync · streaming · background │ │ Runtime Store → crash recovery (Lakebase) │ │ ↓ │ │ Databricks Sandbox │ │ Isolated code execution, scoped UC access │ │ Persistent home directory across calls │ └─────────────────────────────────────────────┘
| Signal | What to watch |
|---|---|
| LTAP GA (H1 2027?) | Layers 3+4 collapse. ETL/CDC pipelines become optional. Most disruptive event for data engineering services. |
| Genie Ontology GA | Current "no cost during preview" ends. Watch pricing model — per-workspace vs per-query. |
| Governance Hub GA | Will likely absorb or productize Ontos Labs features. |
| OSI / Ossie native UI | Snowflake has native SYSTEM$ functions now. Databricks still on community PR #152. |
| IPO 2027 | ~$134B valuation, ~$5.4B ARR. Usage-based pricing must be defensible per product line. |
┌──────────────────────────────────────────────────┐ │ Branded App (Genpact FinanceOne, CitiusTech ClinicalIQ) ├──────────────────────────────────────────────────┤ │ Databricks Apps (FastAPI + React, in workspace) │ ├──────────────────────────────────────────────────┤ │ Genie Spaces │ Agent Bricks │ Lakewatch SIEM│ ├──────────────────────────────────────────────────┤ │ Unity AI Gateway — routing, budgets, audit │ ├──────────────────────────────────────────────────┤ │ Genie Ontology / UC Metric Views (pre-populated)│ ├──────────────────────────────────────────────────┤ │ Lakebase (operational) · Lakehouse//RT (ms) │ ├──────────────────────────────────────────────────┤ │ Unity Catalog — governance, lineage, RBAC │ ├──────────────────────────────────────────────────┤ │ Delta Lake / Lakeflow Zerobus │ └──────────────────────────────────────────────────┘
Vertical IP is what partners pre-build on top: domain Metric Views, pre-populated Genie Ontology snippets, pre-wired Agent Bricks workflows, regulatory governance templates, industry-shaped Apps.
Raw card transactions
└─ Lakeflow Zerobus (gRPC, sub-5s, no broker)
└─ Delta Lake (raw + feature tables)
├─ Spark Real-Time Mode (~5ms e2e)
│ └─ Lakebase customer risk profiles (<300ms reads)
├─ MLflow Model Registry + feature serving
└─ Databricks App (FastAPI + React fraud dashboard)
└─ Unity AI Gateway (audit, spend controls)
Key design: Lakebase replaces external Redis/DynamoDB as the online feature store. No separate operational database. UC governs data and models on one platform for BCBS 239-style lineage.
| Partner | Focus | Key fact |
|---|---|---|
| zeb | Capital markets semantic layer | Pre-certified UC Metric Views (P&L, VaR, sensitivities); 4–6 week deployment vs. typical 6–9 months |
| Genpact FinanceOne | CFO office FP&A | Driver graph across ERP/EPM; NL on KPIs; claims 5%+ EBITDA |
| Neudesic | Payments | Built on Lakebase; unifies transactional + analytical + AI workloads |
| Celebal | Loan origination | 30 days → 4 hours; Omnigent HITL gate before disbursement |
Databricks maintains an open-source hls-skills repo (databricks-industry-solutions, last updated Oct 19, 2026) with PHI detection, genomics cohort queries, RWE cohorts, HEDIS measures, and an evaluation harness.
Vendor-neutral YAML-based interchange format for semantic definitions. Think of it as Parquet for semantic models. Hub-and-spoke model: each platform has a converter to/from Ossie YAML as the hub.
version: "0.1.1"
semantic_model:
- name: finance_model
ai_context: "Use for P&L, revenue, and cost analysis"
datasets:
- name: orders
source: prod_catalog.finance.orders
metrics:
- name: total_revenue
expr:
ANSI_SQL: "SUM(order_amount)"
DATABRICKS: "SUM(order_amount)"
SNOWFLAKE: "SUM(order_amount)"
ai_context: "Primary top-line revenue metric"
Hub-and-spoke ecosystem: dbt MetricFlow → Ossie YAML (reference) · Snowflake native SYSTEM$ functions (GA Aug 2026) · Databricks UC Metric View converter (PR #152, bidirectional) · GoodData, Salesforce, Apache Polaris also listed.
| Entry point | Components | SI effort |
|---|---|---|
| Semantic layer (capital markets) | UC Metric Views + Genie Ontology pre-population | 4–8 weeks (vs. 6–9 months without SI) |
| Fraud detection accelerator | Lakeflow + Lakehouse//RT + Lakebase + MLflow + App | 6–10 weeks |
| Regulatory reporting (BCBS 239) | UC lineage + Metric Views | 8–12 weeks |
| Agentic loan origination | Agent Bricks + Omnigent HITL + Lakebase | 6–8 weeks |
| PHI de-identification (HLS) | UC column masking + hls-skills PHI agent | 2–4 weeks (fast win) |
| Snowflake→Databricks metric migration | dbt MetricFlow → Ossie YAML → UC converter | 1–2 weeks discovery |
UC started as a governance layer (control access to tables and files). The 2024–2026 arc is a deliberate expansion into business semantics: making UC the system that knows what things mean.
Traditional data catalogs (Collibra, Alation, Atlan) were built for data stewards — humans who curate metadata. UC's new semantic layers are explicitly designed for AI agents — machines that query business context at inference time. This is a fundamentally different design target.
Each layer is independently queryable and additive — you don't need Layer 5 before Layer 3 delivers value.
AI-native design: Genie Code drafts new Glossary pages from query patterns, flags definitions that drift from actual usage, surfaces definitions as context when agents query any linked asset. Key differentiator from Collibra/Alation: the glossary is actively maintained by the platform's AI, not just human stewards.
Human-authored markdown context attached to any UC asset. Free-form narrative: "what this dataset is, how to use it, known quirks." UC Pages feed the modeled context side of Genie Ontology — the human voice in the knowledge graph.
Business-aligned groupings of UC assets. Agents scoped to a Domain only retrieve context from that domain's assets — bounded, relevant context instead of the whole catalog. Subdomains supported (Finance > Treasury > Liquidity).
| MCP Endpoint | What it exposes | Auth model |
|---|---|---|
| UC Functions | Any UC-registered function (Python, SQL, system) | OAuth on-behalf-of user |
| Genie Spaces | NL query to a specific Genie Space | OAuth on-behalf-of user |
| SQL Warehouse | Direct SQL against UC-governed tables | OAuth on-behalf-of user |
| Vector Search | Semantic search over indexed UC tables | OAuth on-behalf-of user |
Agent question: "What is our Q3 NPS by region?"
↓
Genie Ontology query (OntoRank retrieval)
→ certified UC Metric View: "net_promoter_score"
→ Domain: "Customer Experience"
→ Glossary term: "NPS" → definition + linked table
→ UC Page: "Survey data — NPS calculation caveats"
↓
Permission check (Unity Catalog)
→ user has read on nps_survey table? Yes
→ column mask on respondent_id? Yes → masked at runtime
↓
Compute: Metric View SQL executed
↓
Answer with source citations from UC lineage
Every agent answer inherits the governance and business meaning that data stewards built into UC.
Collibra/Alation's defense: For enterprises with heterogeneous stacks (Snowflake + Databricks + Oracle + Salesforce), UC only governs the Databricks portion. Catalog Federation is narrowing this gap for some external catalogs.
The coexistence reality: Most Databricks customers have dbt. UC Metric Views and dbt MetricFlow are not mutually exclusive — dbt builds and tests the tables; UC Metric Views define business metrics on top of those tables. Apache Ossie (PR #152) is the portability bridge.
| Feature | Status |
|---|---|
| Technical catalog (tables/schemas/models/volumes) | GA |
| Column-level + cross-cloud lineage | GA |
| UC Metric Views | GA Apr 2 |
| Metric View materialization | Preview |
| Domains | GA Oct 8 |
| Business Glossary | Preview |
| UC Pages | GA |
| Governance Hub | Private Preview |
| Genie Ontology | Public Preview |
| UC MCP Servers | GA |
| Ossie UC Metric View converter | PR #152 open |
"AgentOS" is not an official Databricks product name. It is an industry concept describing the idea that production AI agents need an OS-equivalent: something that handles identity, execution boundaries, memory, permissions, scheduling, and observability.
Databricks framing"Most teams focus on the core agent loop, but that is only 1% of what it actually takes to run agents in production."
The remaining 99% — deployment, security, context grounding, evaluation, memory, cost control, governance, observability — is what Agent Bricks + Omnigent collectively provide.
Key design principle: every agent action is governed by Unity Catalog. A layer-3 policy that denies a git push is enforced before the action reaches the filesystem.
name: code-reviewer
harness: claude-code # swap to: codex, pi, openai-agents (zero other changes)
model: claude-opus-5-5
prompt: |
You are a careful code reviewer. Focus on correctness and security.
tools:
- type: mcp
server: uc-functions # Unity Catalog functions as MCP tools
- type: mcp
server: genie-space
space: risk-metrics
sub_agents:
- name: test-writer
harness: codex
- name: security-scanner
harness: claude-code
skills: [databricks/security-review]
policies:
spend:
warn_at: "$3"
hard_cap: "$5"
actions:
- pattern: "git push"
decision: ask # pause for human approval
- pattern: "DROP TABLE *"
decision: deny # non-negotiable block
Traditional guard rails live in the prompt — which can be circumvented by clever multi-step plans. Omnigent intercepts every action before execution:
| Decision | Behavior |
|---|---|
| allow | Action proceeds immediately |
| ask | Session pauses; notification sent to owner; resumes on approval |
| deny | Action blocked; agent receives a clear refusal and must find another path |
Policies defined at three levels: agent YAML, session override, and platform-wide (Unity AI Gateway, workspace admins). This is the mechanism that lets enterprises say "AI at the helm, humans retain control over irreversible actions" — exactly what regulators in BFSI and HLS need.
Polly (orchestrator — plans, delegates, writes NO code) ├─ Sub-agent A in git worktree 1 (Claude Code) → implementation ├─ Sub-agent B in git worktree 2 (Codex) → tests ├─ Sub-agent C (different vendor than writer) → code review └─ Policy gates applied before any merge/push
Key principles: orchestrator never writes code (avoids context window exhaustion on large tasks) · parallel isolation in git worktrees · cross-vendor review (reviewer uses different model family — correlated blind spots avoided) · spend checks and HITL before final output.
| Capability | Legacy MLflow AgentServer | DurableAgentServer |
|---|---|---|
| Persistent run state | ✗ | ✓ (Runtime Store on Lakebase) |
| Crash recovery | ✗ | ✓ (resumable on restart) |
| Background async runs | ✗ | ✓ |
| Idempotent invocations | ✗ | ✓ |
| Stream resumption | ✗ | ✓ |
| Identity model | Service account | On-behalf-of user (credential held in memory only, never persisted) |
[agent] name = "risk-analyst" description = "Answers risk questions over UC Metric Views" [[tools.mcp]] type = "managed" server = "uc-functions" [[tools.mcp]] type = "managed" server = "genie" space = "risk-metrics" [memory] type = "lakebase" # MemCurrent-backed [sandbox] enabled = true catalog = "prod_catalog" # scoped UC access (only this catalog) [tracing] enabled = true # all tool calls → UC system tables
Three CLI commands: agentbricks init (scaffold) · agentbricks dev (local against live Databricks) · agentbricks deploy (to Agent Runtime on Databricks Apps)
| Phase | What happens |
|---|---|
| 1 Develop | agentbricks init · agent.toml declares tools/memory/sandbox · Omnigent YAML declares harness/policies/sub-agents |
| 2 Iterate | agentbricks dev against live Databricks · MLflow auto-traces every call · GEPA optimize_prompts() against evaluation dataset |
| 3 Evaluate | MLflow evaluation with custom LLM judges · ALHF feedback loop for routing improvement |
| 4 Deploy | agentbricks deploy → Agent Runtime · DurableAgentServer endpoints live · Unity AI Gateway governs |
| 5 Govern | Omnigent policy engine (allow/ask/deny) · AI Gateway cost attribution · MLflow traces → Lakewatch · UC RBAC on all data access |
| 6 Remember | MemCurrent episodic traces → Lakebase · Dreaming: async distillation into derived knowledge |
Each step is on-platform. No separate tool needed for evaluation, secret store, observability, or memory database.
| Dimension | LangGraph / CrewAI | Databricks (Agent Bricks + Omnigent) |
|---|---|---|
| Governance | None built-in | UC RBAC on every tool call |
| Memory | BYO (Redis, Postgres) | MemCurrent on Lakebase (native) |
| Evaluation | LangSmith (separate) / custom | MLflow + GEPA (native) |
| Cost control | None | Omnigent policies + Unity AI Gateway budgets |
| HITL | Interrupt handlers (code) | Omnigent policy YAML (declarative) |
| Deployment | BYO infra | Agent Runtime (managed) |
Every major data platform in 2026 — Databricks, Snowflake, Microsoft Fabric — is building what they each call a "semantic layer." Beneath the marketing, they are converging on the same set of structural design patterns. Naming them gives architects and SIs a vocabulary to evaluate platform maturity, design engagements, and talk to customers without resorting to product brochure language.
These patterns are not product features. They are recurring architectural decisions that appear independently across all three platforms.
The platform is the sovereign of what "revenue" means. Every downstream consumer — dashboards, SQL, agents, APIs — queries the definition from the platform. Sovereignty requires: (1) the definition lives in the platform as a versioned, owned, certifiable object; (2) the platform enforces access to it; (3) business sign-off (certification) is a platform workflow, not a post-it on Confluence.
| Platform | Implementation | Maturity |
|---|---|---|
| Databricks | UC Metric Views — YAML, certification flag, owned by UC principal, open-sourced (UC OSS v0.5) | GA Apr 2026 |
| Snowflake | Semantic Views — native schema objects; replaces earlier YAML-in-a-stage approach | GA 2026 |
| Microsoft Fabric | Power BI Semantic Model — DAX measures, hierarchies, roles; anchored in OneLake via Direct Lake | GA (mature) |
Same metric, five definitions: one in Tableau, one in Power BI, one in the warehouse, one in Python, one in the finance Excel model. Nobody agreed which was correct. Agents trained on all five hallucinated a sixth.
The semantic layer doesn't spring fully-formed from human curation. It develops through behavior — hence ontogenesis, the biological term for an organism developing through its own lifecycle. The formal semantic layer (human-defined) and the behavioral layer (platform-inferred from usage) are maintained in parallel and combined at query time.
| Platform | Formal layer | Behavioral layer | Combination |
|---|---|---|---|
| Databricks | UC Metric Views, Domains, Glossary, UC Pages | Genie Ontology — OntoRank scores snippets from dashboards, SQL history, 50+ apps | Modeled + inferred context, OntoRank rank-blended |
| Snowflake | Semantic Views, custom instructions | Verified queries — operator-curated known-good (Q→SQL) pairs | Semantic View + verified queries at Cortex Analyst query time |
| Fabric | Power BI Semantic Model | Copilot Q&A learning — repeated questions refine understanding | Implicit; least architecturally explicit of the three |
Formal-only: misses the emergent vocabulary (e.g., "whale account" that your sales team uses, which nobody put in the glossary). Behavioral-only: no certified ground truth; agents hallucinate on low-confidence inferences. The pattern is always: two layers, one retrieval. The ranking function is the key design challenge.
Isomorphism (from mathematics): same structure expressed differently. Access to the metric definition and access to the underlying data are the same permission check, not two separate gates. If you can't read the underlying table, you can't compute the metric — and you can't see its definition.
| Platform | Isomorphism mechanism |
|---|---|
| Databricks | UC Metric Views are UC objects → inherit RBAC. All MCP calls use on-behalf-of-user OAuth. Strong — one permission model throughout. |
| Snowflake | Semantic Views are schema-level objects → same RBAC. Caveat: raw SQL tool bypasses semantic view boundary (documented risk — remove raw SQL tool from production agents). |
| Microsoft Fabric | Purview sensitivity labels + OLS (object-level security) in semantic model. Dual enforcement, but requires careful configuration. |
Business glossary terms (which don't contain data but describe it) also inherit data permissions — a new employee may not see the definition of a metric they don't yet have access to compute. All three platforms are still working through this.
Accretion from astrophysics: a body gains mass by pulling in surrounding matter. Here: the "Customer" concept accumulates all the data, metrics, agents, dashboards, and definitions that relate to it, organized by the platform's catalog. This is not a new idea in enterprise architecture — it echoes domain-driven design (DDD) bounded contexts. What is new is that the data platform natively implements it.
| Platform | Concept object | What accretes |
|---|---|---|
| Databricks | Domain (GA Oct 8) + Business Glossary term + UC Pages | Tables, Metric Views, Genie Agents, dashboards, models all belong to a Domain; Glossary term links to implementing assets |
| Snowflake | Horizon Data Product (emerging) + Semantic View entity definitions | Entities model business objects (Customer, Transaction); Cortex Analyst routes through entity model |
| Microsoft Fabric | OneLake Data Hub item + Fabric Business Domains (preview) | Certified datasets, semantic models, reports, notebooks, pipelines browsable per domain |
Databricks Domain ≈ DDD Bounded Context · Snowflake Semantic View entity ≈ DDD Aggregate Root · Fabric Business Domain ≈ DDD shared language. SI teams who know DDD can apply it directly to semantic platform design.
A covenant (not just a contract) implies a mutual, long-term commitment with shared values. Platforms are committing that meaning will not be held hostage. This extends beyond data portability (open table formats) to meaning portability: the business definitions, metric formulas, entity relationships, and domain structures travel with the data.
The three instruments of the covenant: (1) Open table format (Delta/Iceberg — established); (2) Open semantic format (Apache Ossie — in progress 2025–2026); (3) Open catalog standard (Apache Polaris + Ossie YAML stored alongside Iceberg tables — emerging vision).
| Platform | Export | Import | Status |
|---|---|---|---|
| Databricks | PR #152 (UC Metric View → Ossie YAML) | PR #152 (Ossie → UC Metric View) | PR open · no native UI |
| Snowflake | SYSTEM$READ_OSSIE_YAML_FROM_SEMANTIC_VIEW | SYSTEM$CREATE_SEMANTIC_VIEW_FROM_OSSIE_YAML | GA Aug 2026 |
| Microsoft Fabric | TMDL export (open XML) | TMDL import + Ossie→TMDL converter | TMDL GA · converter community |
Snowflake originated Ossie to win the portability narrative. Databricks joined to defend against it. Microsoft joined to ensure TMDL isn't stranded. The Covenant is competitive strategy expressed as openness.
| Pattern | Databricks | Snowflake | Fabric | Overall Maturity |
|---|---|---|---|---|
| 1 · Metric Sovereignty | GA | GA | GA (mature) | Highest — all three in GA |
| 2 · Behavioral Ontogenesis | Most explicit (OntoRank) | Verified queries (operator-curated) | Implicit (Copilot learning) | Medium — Databricks most advanced |
| 3 · Perimeter Isomorphism | Strong (UC RBAC + on-behalf-of) | Good (Snowflake RBAC, raw SQL caveat) | Layered (Purview + OLS) | Medium-high |
| 4 · Concept-Centric Accretion | UC Domains GA Oct 8 + Glossary preview | Horizon data products maturing | Fabric Business Domains preview | Emerging — all three in progress |
| 5 · Open Semantic Covenant | PR #152 open, no native UI | Native GA SYSTEM$ functions (most complete) | TMDL GA, Ossie converter community | Lowest — Snowflake leads |
| Pattern | Databricks | Snowflake | Microsoft Fabric |
|---|---|---|---|
| 1 · Metric Sovereignty | UC Metric Views (GA, open-sourced) | Semantic Views (GA, native objects) | Power BI Semantic Model (mature, DAX) |
| 2 · Behavioral Ontogenesis | Genie Ontology: formal + inferred, OntoRank blending | Verified queries: operator-curated corrections | Copilot Q&A learning (implicit) |
| 3 · Perimeter Isomorphism | UC RBAC on Metric Views + on-behalf-of MCP (strong) | Snowflake RBAC; raw SQL bypass risk (caveat) | Purview labels + OLS in semantic model (layered) |
| 4 · Concept-Centric Accretion | Domains (GA Oct 8) + Glossary (preview) | Horizon data products + Semantic View entity model | OneLake Data Hub + Business Domains (preview) |
| 5 · Open Semantic Covenant | Apache Ossie contributor; PR #152 (no native UI) | Originated Apache Ossie; native SYSTEM$ (GA) | TMDL GA; Ossie→TMDL converter (community) |
| Pattern | Service Offering | Duration | Who buys it |
|---|---|---|---|
| Metric Sovereignty | Semantic Layer Buildout — author UC Metric Views for a business domain | 4–8 weeks per domain | CDO, Head of Analytics, Finance/Risk domain lead |
| Behavioral Ontogenesis | Ontology Quality Audit — review Genie Ontology inferred snippets; replace low-confidence with explicit definitions | 2–3 weeks (recurring) | AI platform team, data governance |
| Perimeter Isomorphism | Semantic Governance Alignment — audit grant structure; close permission gaps | 1–2 weeks | CIO/CISO, data governance |
| Concept-Centric Accretion | Domain Design Workshop + Implementation — DDD approach; UC Domains + Glossary seed + Metric View inventory | 2–3 day workshop + 4–6 week build | CDO, business domain leads |
| Open Semantic Covenant | Semantic Migration Assessment — run Ossie converter; document fidelity gaps; scope migration | 1–2 weeks discovery | CTO, migration program lead |