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Add table metadata

Operational columns and Unity Catalog tags serve different purposes. Columns become part of the data; tags describe tables and columns in Unity Catalog.

Add an ingestion timestamp

Select built-in metadata columns on the action that should add them:

- name: load_orders
  type: load
  source:
    type: cloudfiles
    path: "${landing_path}/orders/*.json"
    format: json
  target: v_orders
  operational_metadata: [_ingestion_timestamp]

To define your own column expression, add it under operational_metadata.columns in lhp.yaml and select its name on the flowgroup or action. Use an explicit list; true alone selects no columns. See Operational metadata for built-in names, applicable target types and selection rules.

Apply Unity Catalog tags

Add a tags mapping to a table’s write_target:

write_target:
  type: streaming_table
  catalog: "${catalog}"
  schema: "${bronze_schema}"
  table: orders
  tags:
    owner: data_platform
    quality: bronze

For shared table and column definitions, use a schema and tags file. Project hook controls belong in lhp.yaml under uc_tagging.

Generate and inspect the resulting Python before deployment. After a pipeline run, check the table’s tags and its event log: tag application uses the run-as identity’s permissions and failures appear as hook warnings. See Troubleshoot a pipeline for diagnosis.