Databricks Unity Catalog

Unity Catalog

Guidance for Unity Catalog governance — access control, the privilege model, external locations, securable DDL, and fine-grained access — plus system tables and volume file operations.

Before running databricks CLI commands, confirm the CLI and the subcommand exist. Run databricks --version — this skill assumes the unified CLI (≥ v1.0.0). Several subcommands shown here (experimental aitools, system-schemas, external-lineage, grants) vary by version or workspace availability; if one is missing or rejects a flag, fall back to the SQL form or the Python SDK rather than guessing. Each reference notes its own version floor where relevant.

When to Use This Skill

Use this skill when:

Governance & access control (start here):

• Granting or revoking access — GRANT/REVOKE, the UC privilege model, ownership (ALTER … OWNER TO), SHOW GRANTS, "who can read/write this table?"
• Row- and column-level security — row filters, column masks, dynamic views with current_user() / is_account_group_member()
• External locations & storage credentials — CREATE STORAGE CREDENTIAL, CREATE EXTERNAL LOCATION, backing external tables/volumes
• Securable DDL & metadata — creating/altering catalogs, schemas, managed vs external tables, views; comments, tags, table properties, ownership

Observability & files:

• Working with volumes (upload, download, list files in /Volumes/)
• Querying lineage (table dependencies, column-level lineage)
• Analyzing audit logs (who accessed what, permission changes)
• Monitoring billing and usage (DBU consumption, cost analysis)
• Tracking compute resources (cluster usage, warehouse metrics)
• Reviewing job execution (run history, success rates, failures)
• Analyzing query performance (slow queries, warehouse utilization)
• Profiling data quality (data profiling, drift detection, metric tables)

Reference Files

Quick Start

Create Unity Catalog Objects (CLI)

Use --json for create commands. Positional argument order differs per command and has changed across CLI versions, so --json is the order-independent, version-stable form shown throughout this skill.

bashCopy code
# Create a catalog
databricks catalogs create --json '{"name": "my_catalog"}'

# Create a schema
databricks schemas create --json '{"name": "my_schema", "catalog_name": "my_catalog"}'

# Create a managed volume
databricks volumes create --json '{
  "catalog_name": "my_catalog",
  "schema_name": "my_schema",
  "name": "my_volume",
  "volume_type": "MANAGED"
}'

# List catalogs, schemas, volumes (read commands take simple positional args)
databricks catalogs list
databricks schemas list my_catalog
databricks volumes list my_catalog.my_schema

Positional create args still work if you prefer them, but the order is not uniform across commands — this is the per-command order (and the reason --json is recommended):

CLI surface varies by version. If a databricks subcommand or positional signature is missing in your install, prefer --json, the SQL form, or the Python SDK rather than guessing flags.

Volume File Operations (CLI)

databricks fs requires the dbfs: scheme prefix even for UC Volume paths — without it the CLI treats the path as local filesystem and errors with no such directory.

bashCopy code
# List files in a volume
databricks fs ls dbfs:/Volumes/catalog/schema/volume/path/

# Upload a directory's contents to a volume (-r copies contents, not the directory itself)
databricks fs cp -r --overwrite /tmp/data dbfs:/Volumes/catalog/schema/volume/dest

# Download a file from a volume
databricks fs cp dbfs:/Volumes/catalog/schema/volume/file.csv /tmp/file.csv

# Create a directory in a volume
databricks fs mkdirs dbfs:/Volumes/catalog/schema/volume/new_folder

Grant & Revoke Access

GRANT/REVOKE is the core governance operation. See references/1-access-control.md for the full privilege model.

sqlCopy code
-- Grant read access on a schema to a group
GRANT USE CATALOG ON CATALOG analytics TO `data_readers`;
GRANT USE SCHEMA ON SCHEMA analytics.gold TO `data_readers`;
GRANT SELECT ON SCHEMA analytics.gold TO `data_readers`;

-- Who can access this table?
SHOW GRANTS ON TABLE analytics.gold.customers;

-- Revoke
REVOKE SELECT ON SCHEMA analytics.gold FROM `data_readers`;

Enable System Tables Access

sqlCopy code
-- Grant access to system tables
GRANT USE CATALOG ON CATALOG system TO `data_engineers`;
GRANT USE SCHEMA ON SCHEMA system.access TO `data_engineers`;
GRANT SELECT ON SCHEMA system.access TO `data_engineers`;

Common Queries

sqlCopy code
-- Table lineage: What tables feed into this table?
SELECT source_table_full_name, source_column_name
FROM system.access.table_lineage
WHERE target_table_full_name = 'catalog.schema.table'
  AND event_date >= current_date() - 7;

-- Audit: Recent permission changes
SELECT event_time, user_identity.email, action_name, request_params
FROM system.access.audit
WHERE action_name LIKE '%GRANT%' OR action_name LIKE '%REVOKE%'
ORDER BY event_time DESC
LIMIT 100;

-- Billing: DBU usage by workspace
SELECT workspace_id, sku_name, SUM(usage_quantity) AS total_dbus
FROM system.billing.usage
WHERE usage_date >= current_date() - 30
GROUP BY workspace_id, sku_name;

Running SQL from the CLI

databricks experimental aitools tools query is an experimental command. The experimental namespace is not guaranteed to be stable across CLI versions and may be absent in your install. Prefer running system-table SQL from a SQL warehouse (SQL editor, scheduled query) or the Python SDK (w.statement_execution.execute_statement), or a notebook. Use the experimental CLI only for quick ad-hoc checks.

Getting the IDs these examples use. WAREHOUSE_ID — run databricks warehouses list (or copy it from a SQL warehouse's Connection details in the UI). METASTORE_ID (used in references/5-system-tables.md) — w.metastores.current().metastore_id via the SDK, or the Catalog UI → metastore details.

Experimental CLI form (convenience only):

bashCopy code
databricks experimental aitools tools query --warehouse WAREHOUSE_ID "
  SELECT source_table_full_name, target_table_full_name
  FROM system.access.table_lineage
  WHERE event_date >= current_date() - 7
"

Stable SDK fallback (works on any CLI version):

pythonCopy code
from databricks.sdk import WorkspaceClient

w = WorkspaceClient()
resp = w.statement_execution.execute_statement(
    warehouse_id="WAREHOUSE_ID",
    statement="""
        SELECT source_table_full_name, target_table_full_name
        FROM system.access.table_lineage
        WHERE event_date >= current_date() - 7
        LIMIT 100
    """,
)
for row in resp.result.data_array or []:
    print(row)

CLI surface varies by version. If a databricks subcommand (e.g. an experimental tool, system-schemas, or external-lineage) is missing, fall back to the SQL warehouse or the Python SDK shown above rather than guessing flags.

Best Practices

1. Grant minimal access - Apply least privilege; grant at the narrowest securable that works
2. Filter by date - System tables can be large; always use date filters
3. Use appropriate retention - Check your workspace's retention settings
4. Schedule reports - Create scheduled queries for regular monitoring
5. Prefer SQL/SDK over experimental CLI - For anything beyond quick checks

Related Skills

This skill owns Unity Catalog governance: access control, the privilege model, external locations / storage credentials, securable DDL, fine-grained access, system tables, and volumes. For adjacent concerns, use the sibling skill instead:

• databricks-core (declared parent) — auth, profile selection, generic CLI, and catalog/table exploration
• databricks-metric-views — metric view definitions / DDL (WITH METRICS LANGUAGE YAML)
• databricks-iceberg — Managed Iceberg, External Iceberg Reads (fka Uniform), and Iceberg REST Catalog (IRC) credential vending for external engines — distinct from UC storage credentials (see references/2-external-locations.md)
• databricks-ml-training — UC model registration and @prod/@challenger aliases
• databricks-vector-search — Vector Search indexes
• databricks-pipelines, databricks-jobs, databricks-lakeflow-connect — producing tables via pipelines/jobs/managed ingestion
• databricks-lakebase — Lakebase / synced tables (OLTP)
• databricks-ai-functions — AI functions such as ai_mask / ai_classify (AI transforms, not access control — see references/4-fine-grained-access.md)
• databricks-aibi-dashboards — AI/BI dashboards on UC data
• databricks-synthetic-data-gen — generating data stored in UC volumes

Roadmap (not yet covered — deferred to a later version)

These governance areas are intentionally out of scope for v0.3.0 and planned for later:

• Delta Sharing / Marketplace / Clean Rooms
• Lakehouse Federation (connections + foreign catalogs)
• ABAC / governed tags as policy

Resources

• Unity Catalog Privileges & Securable Objects
• Unity Catalog System Tables
• Audit Log Reference
• Manage External Locations and Storage Credentials